<?php
        // turn  on warnings and notice during  developement
        include('initialize/PhpErrorSettings.inc.php'); 
	// Project:    Web Reference Database (refbase) <http://www.refbase.net>
	// Copyright:  Matthias Steffens <mailto:refbase@extracts.de> and the file's
	//             original author(s).
	//
	//             This code is distributed in the hope that it will be useful,
	//             but WITHOUT ANY WARRANTY. Please see the GNU General Public
	//             License for more details.
	//
	// File:       ./users.php
	// Repository: $HeadURL: file:///svn/p/refbase/code/branches/bleeding-edge/users.php $
	// Author(s):  Matthias Steffens <mailto:refbase@extracts.de>
	//
	// Created:    29-Jun-03, 00:25
	// Modified:   $Date: 2017-04-13 02:00:18 +0000 (Thu, 13 Apr 2017) $
	//             $Author: karnesky $
	//             $Revision: 1416 $
  //
	// This script shows the admin a list of all user entries available within the 'users' table.
	// User data will be shown in the familiar column view, complete with links to show a user's
	// details and add, edit or delete a user.
	// TODO: I18n


	// Incorporate some include files:
	include 'initialize/db.inc.php'; // 'db.inc.php' is included to hide username and password
	include 'includes/header.inc.php'; // include header
	include 'includes/results_header.inc.php'; // include results header
	include 'includes/footer.inc.php'; // include footer
	include 'includes/include.inc.php'; // include common functions
	include 'initialize/ini.inc.php'; // include common variables

	// --------------------------------------------------------------------

	// START A SESSION:
	// call the 'start_session()' function (from 'include.inc.php') which will also read out available session variables:
	start_session(true);

	// --------------------------------------------------------------------

	// Initialize preferred display language:
	// (note that 'locales.inc.php' has to be included *after* the call to the 'start_session()' function)
	include 'includes/locales.inc.php'; // include the locales

	// --------------------------------------------------------------------

	// Check if the admin is logged in
	if (!(isset($_SESSION['loginEmail']) && ($loginEmail == $adminLoginEmail)))
	{
		// return an appropriate error message:
		$HeaderString = returnMsg("You must be logged in as admin to view any user account details!", "warning", "strong", "HeaderString"); // function 'returnMsg()' is defined in 'include.inc.php'

		// save the URL of the currently displayed page:
		$referer = $_SERVER['HTTP_REFERER'];

		// Write back session variables:
		saveSessionVariable("referer", $referer); // function 'saveSessionVariable()' is defined in 'include.inc.php'

		header("Location: index.php");
		exit;
	}

	// --------------------------------------------------------------------

	// [ Extract form variables sent through POST/GET by use of the '$_REQUEST' variable ]
	// [ !! NOTE !!: for details see <http://www.php.net/release_4_2_1.php> & <http://www.php.net/manual/en/language.variables.predefined.php> ]

	// Extract the form used for searching:
	if (isset($_REQUEST['formType']))
		$formType = $_REQUEST['formType'];
	else
		$formType = "";

	// Extract the type of display requested by the user. Normally, this will be one of the following:
	//  - '' => if the 'submit' parameter is empty, this will produce the default columnar output style ('showUsers()' function)
	//   - 'Add', 'Remove', 'Allow' or 'Disallow' => these values will trigger actions that act on the selected users
	if (isset($_REQUEST['submit']))
		$displayType = $_REQUEST['submit'];
	else
		$displayType = "List";

	// extract the original value of the '$displayType' variable:
	// (which was included as a hidden form tag within the 'groupSearch' form of a search results page)
	if (isset($_REQUEST['originalDisplayType']))
		$originalDisplayType = $_REQUEST['originalDisplayType'];
	else
		$originalDisplayType = "List";

	// For a given display type, extract the view type requested by the user (either 'Mobile', 'Print', 'Web' or ''):
	// ('' will produce the default 'Web' output style)
	if (isset($_REQUEST['viewType']))
		$viewType = $_REQUEST['viewType'];
	else
		$viewType = "";

	// Extract other variables from the request:
	if (isset($_REQUEST['sqlQuery']))
		$sqlQuery = $_REQUEST['sqlQuery'];
	else
		$sqlQuery = "";
	if (preg_match("/%20/", $sqlQuery)) // if '$sqlQuery' still contains URL encoded data... ('%20' is the URL encoded form of a space, see note below!)
		$sqlQuery = rawurldecode($sqlQuery); // URL decode SQL query (it was URL encoded before incorporation into hidden tags of the 'groupSearch', 'refineSearch', 'displayOptions' and 'queryResults' forms to avoid any HTML syntax errors)
											// NOTE: URL encoded data that are included within a *link* will get URL decoded automatically *before* extraction via '$_REQUEST'!
											//       But, opposed to that, URL encoded data that are included within a form by means of a hidden form tag will *NOT* get URL decoded automatically! Then, URL decoding has to be done manually (as is done here)!

	if (isset($_REQUEST['showQuery']) AND ($_REQUEST['showQuery'] == "1"))
		$showQuery = "1";
	else
		$showQuery = "0"; // don't show the SQL query by default

	if (isset($_REQUEST['showLinks']) AND ($_REQUEST['showLinks'] == "0"))
		$showLinks = "0";
	else
		$showLinks = "1"; // show the links column by default

	if (isset($_REQUEST['showRows']) AND preg_match("/^[1-9]+[0-9]*$/", $_REQUEST['showRows']))
		$showRows = $_REQUEST['showRows'];
	else
		$showRows = $_SESSION['userRecordsPerPage']; // get the default number of records per page preferred by the current user

	if (isset($_REQUEST['rowOffset']))
		$rowOffset = $_REQUEST['rowOffset'];
	else
		$rowOffset = "";

	// Extract checkbox variable values from the request:
	if (isset($_REQUEST['marked']))
		$recordSerialsArray = $_REQUEST['marked']; // extract the values of all checked checkboxes (i.e., the serials of all selected records)
	else
		$recordSerialsArray = array();

	// check if the user did mark any checkboxes (and set up variables accordingly)
	if (empty($recordSerialsArray)) // no checkboxes were marked
		$nothingChecked = true;
	else // some checkboxes were marked
		$nothingChecked = false;

	// --------------------------------------------------------------------

	// CONSTRUCT SQL QUERY:

	// --- Embedded sql query: ----------------------
	if ($formType == "sqlSearch") // the admin used a link with an embedded sql query for searching...
	{
		$query = preg_replace("/ FROM $tableUsers/i",", user_id FROM $tableUsers",$sqlQuery); // add 'user_id' column (which is required in order to obtain unique checkbox names as well as for use in the 'getUserID()' function)
		$query = stripSlashesIfMagicQuotes($query);
	}

	// --- 'Search within Results' & 'Display Options' forms within 'users.php': ---------------
	elseif ($formType == "refineSearch" OR $formType == "displayOptions") // the user used the "Search within Results" (or "Display Options") form above the query results list (that was produced by 'users.php')
	{
		list($query, $displayType) = extractFormElementsRefineDisplay($tableUsers, $displayType, $originalDisplayType, $sqlQuery, $showLinks, "", ""); // function 'extractFormElementsRefineDisplay()' is defined in 'include.inc.php' since it's also used by 'users.php'
	}

	// --- 'Show User Group' form within 'users.php': ---------------------
	elseif ($formType == "groupSearch") // the user used the 'Show User Group' form above the query results list (that was produced by 'users.php')
	{
		$query = extractFormElementsGroup($sqlQuery);
	}

	// --- Query results form within 'users.php': ---------------
	elseif ($formType == "queryResults") // the user clicked one of the buttons under the query results list (that was produced by 'users.php')
	{
		list($query, $displayType) = extractFormElementsQueryResults($displayType, $originalDisplayType, $sqlQuery, $recordSerialsArray);
	}

	else // build the default query:
	{
		$query = "SELECT first_name, last_name, abbrev_institution, email, last_login, logins, user_id FROM $tableUsers WHERE user_id RLIKE \".+\" ORDER BY last_login DESC, last_name, first_name";
	}


	// ----------------------------------------------

	// (1) OPEN CONNECTION, (2) SELECT DATABASE
	connectToMySQLDatabase(); // function 'connectToMySQLDatabase()' is defined in 'include.inc.php'

	// (3) RUN the query on the database through the connection:
	$result = queryMySQLDatabase($query); // function 'queryMySQLDatabase()' is defined in 'include.inc.php'

	// ----------------------------------------------

	// (4a) DISPLAY header:
	$query = preg_replace("/, user_id FROM $tableUsers/i"," FROM $tableUsers",$query); // strip 'user_id' column from SQL query (so that it won't get displayed in query strings)

	$queryURL = rawurlencode($query); // URL encode SQL query

	// First, find out how many rows are available:
	$rowsFound = @ mysqli_num_rows($result);
	if ($rowsFound > 0) // If there were rows found ...
		{
			// ... setup variables in order to facilitate "previous" & "next" browsing:
			// a) Set '$rowOffset' to zero if not previously defined, or if a wrong number (<=0) was given
			if (empty($rowOffset) || ($rowOffset <= 0) || ($showRows >= $rowsFound)) // the third condition is only necessary if '$rowOffset' gets embedded within the 'displayOptions' form (see function 'buildDisplayOptionsElements()' in 'include.inc.php')
				$rowOffset = 0;

			// Adjust the '$showRows' value if not previously defined, or if a wrong number (<=0 or float) was given
			if (empty($showRows) || ($showRows <= 0) || !preg_match("/^[0-9]+$/", $showRows))
				$showRows = $_SESSION['userRecordsPerPage']; // get the default number of records per page preferred by the current user

			// NOTE: The current value of '$rowOffset' is embedded as hidden tag within the 'displayOptions' form. By this, the current row offset can be re-applied
			//       after the user pressed the 'Show'/'Hide' button within the 'displayOptions' form. But then, to avoid that browse links don't behave as expected,
			//       we need to adjust the actual value of '$rowOffset' to an exact multiple of '$showRows':
			$offsetRatio = ($rowOffset / $showRows);
			if (!is_integer($offsetRatio)) // check whether the value of the '$offsetRatio' variable is not an integer
			{ // if '$offsetRatio' is a float:
				$offsetCorrectionFactor = floor($offsetRatio); // get it's next lower integer
				if ($offsetCorrectionFactor != 0)
					$rowOffset = ($offsetCorrectionFactor * $showRows); // correct the current row offset to the closest multiple of '$showRows' *below* the current row offset
				else
					$rowOffset = 0;
			}

			// b) The "Previous" page begins at the current offset LESS the number of rows per page
			$previousOffset = $rowOffset - $showRows;

			// c) The "Next" page begins at the current offset PLUS the number of rows per page
			$nextOffset = $rowOffset + $showRows;

			// d) Seek to the current offset
			mysqli_data_seek($result, $rowOffset);
		}
	else // set variables to zero in order to prevent 'Undefined variable...' messages when nothing was found ('$rowsFound = 0'):
		{
			$rowOffset = 0;
			$previousOffset = 0;
			$nextOffset = 0;
		}

	// Second, calculate the maximum result number on each page ('$showMaxRow' is required as parameter to the 'displayDetails()' function)
	if (($rowOffset + $showRows) < $rowsFound)
		$showMaxRow = ($rowOffset + $showRows); // maximum result number on each page
	else
		$showMaxRow = $rowsFound; // for the last results page, correct the maximum result number if necessary

	// Third, build the appropriate header string (which is required as parameter to the 'showPageHeader()' function):
	if (!isset($_SESSION['HeaderString'])) // if there's no stored message available provide the default message:
	{
		if ($rowsFound == 1)
			$HeaderString = " user found:";
		else
			$HeaderString = " users found:";

		if ($rowsFound > 0)
			$HeaderString = ($rowOffset + 1) . "-" . $showMaxRow . " of " . $rowsFound . $HeaderString;
		elseif ($rowsFound == 0)
			$HeaderString = $rowsFound . $HeaderString;
	}
	else
	{
		$HeaderString = $_SESSION['HeaderString']; // extract 'HeaderString' session variable (only necessary if register globals is OFF!)

		// Note: though we clear the session variable, the current message is still available to this script via '$HeaderString':
		deleteSessionVariable("HeaderString"); // function 'deleteSessionVariable()' is defined in 'include.inc.php'
	}

	// Now, show the login status:
	showLogin(); // (function 'showLogin()' is defined in 'include.inc.php')

	// Then, call the 'displayHTMLhead()' and 'showPageHeader()' functions (which are defined in 'header.inc.php'):
	displayHTMLhead(encodeHTML($officialDatabaseName) . " -- Manage Users", "noindex,nofollow", "Administration page that lists users of the " . encodeHTML($officialDatabaseName) . ", with links for adding, editing or deleting any users", "", true, "", $viewType, array());
	if (!preg_match("/^(Print|Mobile)$/i", $viewType)) // Note: we omit the visible header in print/mobile view! ('viewType=Print' or 'viewType=Mobile')
		showPageHeader($HeaderString);

	// (4b) DISPLAY results:
	showUsers($result, $rowsFound, $query, $queryURL, $showQuery, $showLinks, $rowOffset, $showRows, $previousOffset, $nextOffset, $showMaxRow, $viewType, $displayType); // show all users

	// ----------------------------------------------

	// (5) CLOSE the database connection:
	disconnectFromMySQLDatabase(); // function 'disconnectFromMySQLDatabase()' is defined in 'include.inc.php'

	// --------------------------------------------------------------------

	// Display all users listed within the 'users' table
	function showUsers($result, $rowsFound, $query, $queryURL, $showQuery, $showLinks, $rowOffset, $showRows, $previousOffset, $nextOffset, $showMaxRow, $viewType, $displayType)
	{
		global $connection;
		global $HeaderString;
		global $loginWelcomeMsg;
		global $loginStatus;
		global $loginLinks;
		global $loginEmail;
		global $adminLoginEmail;
		global $defaultCiteStyle;
		global $maximumBrowseLinks;

		global $loc; // '$loc' is made globally available in 'core.php'

		if ($rowsFound > 0) // If the query has results ...
		{
			// BEGIN RESULTS HEADER --------------------
			// 1) First, initialize some variables that we'll need later on
			// Note: In contrast to 'search.php', we don't hide any columns but the user_id column (see below)
			//       However, in order to maintain a similar code structure to 'search.php' we define $CounterMax here as well & simply set it to 0:
			$CounterMax = "0";

			// count the number of fields
			$fieldsFound = mysqli_num_fields($result);
			// hide those last columns that were added by the script and not by the user
			$fieldsToDisplay = $fieldsFound-(1+$CounterMax); // (1+$CounterMax) -> $CounterMax is increased by 1 in order to hide the user_id column (which was added to make the checkbox work)

			// Calculate the number of all visible columns (which is needed as colspan value inside some TD tags)
			if ($showLinks == "1")
				$NoColumns = (1+$fieldsToDisplay+1); // add checkbox & Links column
			else
				$NoColumns = (1+$fieldsToDisplay); // add checkbox column

			// Note: we omit the results header in print/mobile view! ('viewType=Print' or 'viewType=Mobile')
			if (!preg_match("/^(Print|Mobile)$/i", $viewType))
			{
				// Specify which colums are available in the popup menus of the results header:
				$dropDownFieldsArray = array("first_name"            => "first_name",
				                             "last_name"             => "last_name",
				                             "title"                 => "title",
				                             "institution"           => "institution",
				                             "abbrev_institution"    => "abbrev_institution",
				                             "corporate_institution" => "corporate_institution",
				                             "address_line_1"        => "address_line_1",
				                             "address_line_2"        => "address_line_2",
				                             "address_line_3"        => "address_line_3",
				                             "zip_code"              => "zip_code",
				                             "city"                  => "city",
				                             "state"                 => "state",
				                             "country"               => "country",
				                             "phone"                 => "phone",
				                             "email"                 => "email",
				                             "url"                   => "url",
				                             "language"              => "language",
				                             "keywords"              => "keywords",
				                             "notes"                 => "notes",
				                             "marked"                => "marked",
				                             "last_login"            => "last_login",
				                             "logins"                => "logins",
				                             "user_id"               => "user_id",
				                             "user_groups"           => "user_groups",
				                             "created_date"          => "created_date",
				                             "created_time"          => "created_time",
				                             "created_by"            => "created_by",
				                             "modified_date"         => "modified_date",
				                             "modified_time"         => "modified_time",
				                             "modified_by"           => "modified_by"
				                            );

				// Extract the first field from the 'WHERE' clause:
				if (preg_match("/ WHERE [ ()]*(\w+)/i", $query))
					$selectedField = preg_replace("/.+ WHERE [ ()]*(\w+).*/i", "\\1", $query);
				else
					$selectedField = "last_name"; // in the 'Search within Results" form, we'll select the 'last_name' field by default

				// Build a TABLE with forms containing options to show the user groups, refine the search results or change the displayed columns:

				//    - Build a FORM with a popup containing the user groups:
				$formElementsGroup = buildGroupSearchElements("users.php", $queryURL, $query, $showQuery, $showLinks, $showRows, $defaultCiteStyle, "", $displayType); // function 'buildGroupSearchElements()' is defined in 'include.inc.php'

				//    - Build a FORM containing options to refine the search results:
				//      Call the 'buildRefineSearchElements()' function (defined in 'include.inc.php') which does the actual work:
				$formElementsRefine = buildRefineSearchElements("users.php", $queryURL, $showQuery, $showLinks, $showRows, $defaultCiteStyle, "", $dropDownFieldsArray, $selectedField, $displayType);

				//    - Build a FORM containing display options (show/hide columns or change the number of records displayed per page):
				//      Call the 'buildDisplayOptionsElements()' function (defined in 'include.inc.php') which does the actual work:
				$formElementsDisplayOptions = buildDisplayOptionsElements("users.php", $queryURL, $showQuery, $showLinks, $rowOffset, $showRows, $defaultCiteStyle, "", $dropDownFieldsArray, $selectedField, $fieldsToDisplay, $displayType, "");

				echo displayResultsHeader("users.php", $formElementsGroup, $formElementsRefine, $formElementsDisplayOptions, $displayType); // function 'displayResultsHeader()' is defined in 'results_header.inc.php'
			}


			// and insert a divider line (which separates the results header from the browse links & results data below):
			if (!preg_match("/^(Print|Mobile)$/i", $viewType)) // Note: we omit the divider line in print/mobile view! ('viewType=Print' or 'viewType=Mobile')
				echo "\n<hr class=\"resultsheader\" align=\"center\" width=\"93%\">";

			// Build a TABLE with links for "previous" & "next" browsing, as well as links to intermediate pages
			// call the 'buildBrowseLinks()' function (defined in 'include.inc.php'):
			$BrowseLinks = buildBrowseLinks("users.php", $query, $NoColumns, $rowsFound, $showQuery, $showLinks, $showRows, $rowOffset, $previousOffset, $nextOffset, "1", $maximumBrowseLinks, "sqlSearch", $displayType, $defaultCiteStyle, "", "", "", $viewType); // Note: we set the last 3 fields ('$citeOrder', '$orderBy' & $headerMsg') to "" since they aren't (yet) required here
			echo $BrowseLinks;


			// Start a FORM
			echo "\n<form action=\"users.php\" method=\"GET\" name=\"queryResults\">"
					. "\n<input type=\"hidden\" name=\"formType\" value=\"queryResults\">"
					. "\n<input type=\"hidden\" name=\"submit\" value=\"Add\">" // provide a default value for the 'submit' form tag (then, hitting <enter> within the 'ShowRows' text entry field will act as if the user clicked the 'Add' button)
					. "\n<input type=\"hidden\" name=\"showRows\" value=\"$showRows\">" // embed the current values of '$showRows', '$rowOffset' and the current sqlQuery so that they can be re-applied after the user pressed the 'Add' or 'Remove' button within the 'queryResults' form
					. "\n<input type=\"hidden\" name=\"rowOffset\" value=\"$rowOffset\">"
					. "\n<input type=\"hidden\" name=\"sqlQuery\" value=\"$queryURL\">";

			// And start a TABLE
			echo "\n<table id=\"columns\" class=\"results\" align=\"center\" border=\"0\" cellpadding=\"5\" cellspacing=\"0\" width=\"95%\" summary=\"This table displays users of this database\">";

			// For the column headers, start another TABLE ROW ...
			echo "\n<tr>";

			// ... print a marker ('x') column (which will hold the checkboxes within the results part)
			if (!preg_match("/^(Print|Mobile)$/i", $viewType)) // Note: we omit the marker column in print/mobile view! ('viewType=Print' or 'viewType=Mobile')
				echo "\n\t<th align=\"left\" valign=\"top\">&nbsp;</th>";

			// for each of the attributes in the result set...
			for ($i=0; $i<$fieldsToDisplay; $i++)
			{
				// ...print out each of the attribute names
				// in that row as a separate TH (Table Header)...
				$HTMLbeforeLink = "\n\t<th align=\"left\" valign=\"top\">"; // start the table header tag
				$HTMLafterLink = "</th>"; // close the table header tag
				// call the 'buildFieldNameLinks()' function (defined in 'include.inc.php'), which will return a properly formatted table header tag holding the current field's name
				// as well as the URL encoded query with the appropriate ORDER clause:
				$tableHeaderLink = buildFieldNameLinks("users.php", $query, "", $result, $i, $showQuery, $showLinks, $rowOffset, $showRows, "1", $defaultCiteStyle, $HTMLbeforeLink, $HTMLafterLink, "sqlSearch", $displayType, "", "", "", $viewType);
				echo $tableHeaderLink; // print the attribute name as link
			 }

			if ($showLinks == "1")
				{
					$newORDER = ("ORDER BY user_id"); // Build the appropriate ORDER BY clause to facilitate sorting by Links column

					$HTMLbeforeLink = "\n\t<th align=\"left\" valign=\"top\">"; // start the table header tag
					$HTMLafterLink = "</th>"; // close the table header tag
					// call the 'buildFieldNameLinks()' function (defined in 'include.inc.php'), which will return a properly formatted table header tag holding the current field's name
					// as well as the URL encoded query with the appropriate ORDER clause:
					$tableHeaderLink = buildFieldNameLinks("users.php", $query, $newORDER, $result, $i, $showQuery, $showLinks, $rowOffset, $showRows, "1", $defaultCiteStyle, $HTMLbeforeLink, $HTMLafterLink, "sqlSearch", $displayType, $loc["Links"], "user_id", "", $viewType);
					echo $tableHeaderLink; // print the attribute name as link
				}

			// Finish the row
			echo "\n</tr>";
			// END RESULTS HEADER ----------------------

        // display default user
        echo "<tr class=\"odd\">";
        echo "<td align=\"left\" valign=\"top\" width=\"10\"><input DISABLED type=\"checkbox\"</td>";
        echo "<td valign=\"top\"colspan=2>Account options for anyone who isn't logged in</td>";
        echo "<td valign=\"top\">-</td><td valign=\"top\">-</td><td valign=\"top\">-</td><td valign=\"top\">-</td>";
        echo "<td><a href=\"user_options.php?userID=0". "\"><img src=\"img/options.gif\" alt=\""
        . $loc["options"] . "\" title=\"" . $loc["LinkTitle_EditOptions"] . "\" width=\"11\" height=\"17\" hspace=\"0\" border=\"0\"></a></td>";
        echo "</tr>";

			// BEGIN RESULTS DATA COLUMNS --------------
			for ($rowCounter=0; (($rowCounter < $showRows) && ($row = @ mysqli_fetch_array($result))); $rowCounter++)
			{
				if (is_integer($rowCounter / 2)) // if we currently are at an even number of rows
					$rowClass = "even";
				else
					$rowClass = "odd";

				// ... start a TABLE ROW ...
				echo "\n<tr class=\"" . $rowClass . "\">";

				// ... print a column with a checkbox
				if (!preg_match("/^(Print|Mobile)$/i", $viewType)) // Note: we omit the marker column in print/mobile view! ('viewType=Print' or 'viewType=Mobile')
					echo "\n\t<td align=\"left\" valign=\"top\" width=\"10\"><input type=\"checkbox\" name=\"marked[]\" value=\"" . $row["user_id"] . "\"></td>";

				// ... and print out each of the attributes
				// in that row as a separate TD (Table Data)
				for ($i=0; $i<$fieldsToDisplay; $i++)
				{
					// fetch the current attribute name:
					$orig_fieldname = getMySQLFieldInfo($result, $i, "name"); // function 'getMySQLFieldInfo()' is defined in 'include.inc.php'

					if (preg_match("/^email$/", $orig_fieldname))
						echo "\n\t<td valign=\"top\"><a href=\"mailto:" . $row["email"] . "\">" . $row["email"] . "</a></td>";
					elseif (preg_match("/^url$/", $orig_fieldname) AND !empty($row["url"]))
						echo "\n\t<td valign=\"top\"><a href=\"" . $row["url"] . "\">" . $row["url"] . "</a></td>";
					else
						echo "\n\t<td valign=\"top\">" . encodeHTML($row[$i]) . "</td>";
				}

				// embed appropriate links (if available):
				if ($showLinks == "1")
				{
					echo "\n\t<td valign=\"top\">";

					echo "\n\t\t<a href=\"user_receipt.php?userID=" . $row["user_id"]
						. "\"><img src=\"img/details.gif\" alt=\"" . $loc["details"] . "\" title=\"" . $loc["LinkTitle_ShowDetailsAndOptions"] . "\" width=\"9\" height=\"17\" hspace=\"0\" border=\"0\"></a>&nbsp;&nbsp;";

					echo "\n\t\t<a href=\"user_details.php?userID=" . $row["user_id"]
						. "\"><img src=\"img/edit.gif\" alt=\"" . $loc["edit"] . "\" title=\"" . $loc["LinkTitle_EditDetails"] . "\" width=\"11\" height=\"17\" hspace=\"0\" border=\"0\"></a>&nbsp;&nbsp;";

					echo "\n\t\t<a href=\"user_options.php?userID=" . $row["user_id"]
						. "\"><img src=\"img/options.gif\" alt=\"" . $loc["options"] . "\" title=\"" . $loc["LinkTitle_EditOptions"] . "\" width=\"11\" height=\"17\" hspace=\"0\" border=\"0\"></a>&nbsp;&nbsp;";

					$adminUserID = getUserID($adminLoginEmail); // ...get the admin's 'user_id' using his/her 'adminLoginEmail' (function 'getUserID()' is defined in 'include.inc.php')
					if ($row["user_id"] != $adminUserID) // we only provide a delete link if this user isn't the admin:
						echo "\n\t\t<a href=\"user_receipt.php?userID=" . $row["user_id"] . "&amp;userAction=Delete"
							. "\"><img src=\"img/delete.gif\" alt=\"" . $loc["delete"] . "\" title=\"" . $loc["LinkTitle_DeleteUser"] . "\" width=\"11\" height=\"17\" hspace=\"0\" border=\"0\"></a>";

					echo "\n\t</td>";
				}
				// Finish the row
				echo "\n</tr>";
			}
			// Then, finish the table
			echo "\n</table>";
			// END RESULTS DATA COLUMNS ----------------

			// BEGIN RESULTS FOOTER --------------------
			// Note: we omit the results footer in print/mobile view! ('viewType=Print' or 'viewType=Mobile')
			if (!preg_match("/^(Print|Mobile)$/i", $viewType))
			{
				// Again, insert the (already constructed) BROWSE LINKS
				// (i.e., a TABLE with links for "previous" & "next" browsing, as well as links to intermediate pages)
				echo $BrowseLinks;

				// Insert a divider line (which separates the results data from the results footer):
				echo "\n<hr class=\"resultsfooter\" align=\"center\" width=\"93%\">";

				// Build a TABLE containing rows with buttons which will trigger actions that act on the selected users
				// Call the 'buildUserResultsFooter()' function (which does the actual work):
				$userResultsFooter = buildUserResultsFooter($NoColumns);
				echo $userResultsFooter;
			}
			// END RESULTS FOOTER ----------------------

			// Finally, finish the form
			echo "\n</form>";
		}
		else
		{
			// Report that nothing was found:
			echo "\n<table id=\"error\" class=\"results\" align=\"center\" border=\"0\" cellpadding=\"0\" cellspacing=\"10\" width=\"95%\" summary=\"This table displays users of this database\">"
					. "\n<tr>"
					. "\n\t<td valign=\"top\">Sorry, but your query didn't produce any results!&nbsp;&nbsp;<a href=\"javascript:history.back()\">Go Back</a></td>"
					. "\n</tr>"
					. "\n</table>";
		}// end if $rowsFound body
	}

	// --------------------------------------------------------------------

	//	BUILD USER RESULTS FOOTER
	// (i.e., build a TABLE containing a row with buttons for assigning selected users to a particular group)
	function buildUserResultsFooter($NoColumns)
	{
		global $loc; // '$loc' is made globally available in 'core.php'

		// Start a TABLE
		$userResultsFooterRow = "\n<table class=\"resultsfooter\" align=\"center\" border=\"0\" cellpadding=\"0\" cellspacing=\"10\" width=\"90%\" summary=\"This table holds the results footer which offers a form to assign selected users to a group and set their permissions\">";

		$userResultsFooterRow .= "\n<tr>"

								. "\n\t<td align=\"left\" valign=\"top\">"
								. "Selected Users:"
								. "</td>";

		// Admin user groups functionality:
		if (!isset($_SESSION['adminUserGroups']))
		{
			$groupSearchDisabled = " disabled"; // disable the (part of the) 'Add to/Remove from group' form elements if the session variable holding the admin's user groups isn't available
			$groupSearchPopupMenuChecked = "";
			$groupSearchTextInputChecked = " checked";
			$groupSearchSelectorTitle = "(to setup a new group with all selected users, enter a group name to the right, then click the 'Add' button)";
			$groupSearchTextInputTitle = "to setup a new group with the selected users, specify the name of the group here, then click the 'Add' button";
		}
		else
		{
			$groupSearchDisabled = "";
			$groupSearchPopupMenuChecked = " checked";
			$groupSearchTextInputChecked = "";
			$groupSearchSelectorTitle = "choose the group to which the selected users shall belong (or from which they shall be removed)";
			$groupSearchTextInputTitle = "to setup a new group with the selected users, click the radio button to the left &amp; specify the name of the group here, then click the 'Add' button";
		}

		$userResultsFooterRow .= "\n\t<td align=\"left\" valign=\"top\" colspan=\"" . ($NoColumns - 1) . "\">"
								. "\n\t\t<input type=\"submit\" name=\"submit\" value=\"Add\" title=\"add all selected users to the specified group\">&nbsp;"
								. "\n\t\t<input type=\"submit\" name=\"submit\" value=\"Remove\" title=\"remove all selected users from the specified group\"$groupSearchDisabled>&nbsp;&nbsp;&nbsp;group:&nbsp;&nbsp;"
								. "\n\t\t<input type=\"radio\" name=\"userGroupActionRadio\" value=\"1\" title=\"click here if you want to add (remove) the selected users to (from) an existing group; then, choose the group name from the popup menu to the right\"$groupSearchDisabled$groupSearchPopupMenuChecked>"
								. "\n\t\t<select name=\"userGroupSelector\" title=\"$groupSearchSelectorTitle\"$groupSearchDisabled>";

		if (!isset($_SESSION['adminUserGroups']))
		{
			$userResultsFooterRow .= "\n\t\t\t<option>(no groups available)</option>";
		}
		else
		{
			$optionTags = buildSelectMenuOptions($_SESSION['adminUserGroups'], "/ *; */", "\t\t\t", false); // build properly formatted <option> tag elements from the items listed in the 'adminUserGroups' session variable
			$userResultsFooterRow .= $optionTags;
		}

		$userResultsFooterRow .= "\n\t\t</select>&nbsp;&nbsp;&nbsp;"
								. "\n\t\t<input type=\"radio\" name=\"userGroupActionRadio\" value=\"0\" title=\"click here if you want to setup a new group; then, enter the group name in the text box to the right\"$groupSearchTextInputChecked>"
								. "\n\t\t<input type=\"text\" name=\"userGroupName\" value=\"\" size=\"8\" title=\"$groupSearchTextInputTitle\">"
								. "\n\t</td>"

								. "\n</tr>";

		// Set user permissions functionality:
		$userResultsFooterRow .= "\n<tr>"

								. "\n\t<td align=\"left\" valign=\"top\">&nbsp;</td>"

								. "\n\t<td align=\"left\" valign=\"top\" colspan=\"" . ($NoColumns - 1) . "\">"
								. "\n\t\t<input type=\"submit\" name=\"submit\" value=\"Allow\" title=\"allow all selected users to use the specified feature\">&nbsp;"
								. "\n\t\t<input type=\"submit\" name=\"submit\" value=\"Disallow\" title=\"do not allow the selected users to use the specified feature\">&nbsp;&nbsp;&nbsp;feature:&nbsp;&nbsp;"
								. "\n\t\t<select name=\"userPermissionSelector\" title=\"select the permission setting you'd like to change for the selected users\">";

		// Map raw field names from table 'user_permissions' with items of the global localization array ('$loc'):
		$userPermissionsArray = array('allow_add'                => $loc['UserPermission_AllowAdd'],
										'allow_edit'             => $loc['UserPermission_AllowEdit'],
										'allow_delete'           => $loc['UserPermission_AllowDelete'],
										'allow_download'         => $loc['UserPermission_AllowDownload'],
										'allow_upload'           => $loc['UserPermission_AllowUpload'],
										'allow_list_view'        => $loc['UserPermission_AllowListView'],
										'allow_details_view'     => $loc['UserPermission_AllowDetailsView'],
										'allow_print_view'       => $loc['UserPermission_AllowPrintView'],
//										'allow_browse_view'      => $loc['UserPermission_AllowBrowseView'],
										'allow_sql_search'       => $loc['UserPermission_AllowSQLSearch'],
										'allow_user_groups'      => $loc['UserPermission_AllowUserGroups'],
										'allow_user_queries'     => $loc['UserPermission_AllowUserQueries'],
										'allow_rss_feeds'        => $loc['UserPermission_AllowRSSFeeds'],
										'allow_import'           => $loc['UserPermission_AllowImport'],
										'allow_export'           => $loc['UserPermission_AllowExport'],
										'allow_cite'             => $loc['UserPermission_AllowCite'],
										'allow_batch_import'     => $loc['UserPermission_AllowBatchImport'],
										'allow_batch_export'     => $loc['UserPermission_AllowBatchExport'],
										'allow_modify_options'   => $loc['UserPermission_AllowModifyOptions']);
//										'allow_edit_call_number' => $loc['UserPermission_AllowEditCallNumber']);

		$optionTags = buildSelectMenuOptions($userPermissionsArray, "//", "\t\t\t", true); // build properly formatted <option> tag elements from the items listed in the '$userPermissionsArray' variable
		$userResultsFooterRow .= $optionTags;

		$userResultsFooterRow .= "\n\t\t</select>"
								. "\n\t</td>"

								. "\n</tr>";

		// Finish the table:
		$userResultsFooterRow .= "\n</table>";

		return $userResultsFooterRow;
	}

	// --------------------------------------------------------------------

	// Build the database query from user input provided by the "Show User Group" form above the query results list (that was produced by 'users.php'):
	function extractFormElementsGroup($sqlQuery)
	{
		global $tableUsers; // defined in 'db.inc.php'

		if (!empty($sqlQuery)) // if there's a previous SQL query available
		{
			// use the custom set of colums chosen by the user:
			$query = "SELECT " . extractSELECTclause($sqlQuery); // function 'extractSELECTclause()' is defined in 'include.inc.php'

			// user the custom ORDER BY clause chosen by the user:
			$queryOrderBy = extractORDERBYclause($sqlQuery); // function 'extractORDERBYclause()' is defined in 'include.inc.php'
		}
		else
		{
			$query = "SELECT first_name, last_name, abbrev_institution, email, last_login, logins, user_id"; // use the default SELECT statement
			$queryOrderBy = "last_login DESC, last_name, first_name"; // add the default ORDER BY clause
		}

		$groupSearchSelector = $_REQUEST['groupSearchSelector']; // extract the user group chosen by the user

		$query .= ", user_id"; // add 'user_id' column (although it won't be visible the 'user_id' column gets included in every search query)
								// (which is required in order to obtain unique checkbox names as well as for use in the 'getUserID()' function)

		$query .= " FROM $tableUsers"; // add FROM clause

		$query .= " WHERE user_groups RLIKE " . quote_smart("(^|.*;) *" . $groupSearchSelector . " *(;.*|$)"); // add WHERE clause

		$query .= " ORDER BY " . $queryOrderBy; // add ORDER BY clause


		return $query;
	}

	// --------------------------------------------------------------------

	// Build the database query from records selected by the user within the query results list (which, in turn, was returned by 'users.php'):
	function extractFormElementsQueryResults($displayType, $originalDisplayType, $sqlQuery, $recordSerialsArray)
	{
		global $tableUsers; // defined in 'db.inc.php'

		$userGroupActionRadio = $_REQUEST['userGroupActionRadio']; // extract user option whether we're supposed to process an existing group name or any custom/new group name that was specified by the user

		// Extract the chosen user group from the request:
		// first, we need to check whether the user did choose an existing group name from the popup menu
		// -OR- if he/she did enter a custom group name in the text entry field:
		if ($userGroupActionRadio == "1") // if the user checked the radio button next to the group popup menu ('userGroupSelector') [this is the default]
		{
			if (isset($_REQUEST['userGroupSelector']))
				$userGroup = $_REQUEST['userGroupSelector']; // extract the value of the 'userGroupSelector' popup menu
			else
				$userGroup = "";
		}
		else // $userGroupActionRadio == "0" // if the user checked the radio button next to the group text entry field ('userGroupName')
		{
			if (isset($_REQUEST['userGroupName']))
				$userGroup = $_REQUEST['userGroupName']; // extract the value of the 'userGroupName' text entry field
			else
				$userGroup = "";
		}

		// extract the specified permission setting:
		if (isset($_REQUEST['userPermissionSelector']))
			$userPermission = $_REQUEST['userPermissionSelector']; // extract the value of the 'userPermissionSelector' popup menu
		else
			$userPermission = "";


		if (!empty($recordSerialsArray))
		{
			if (preg_match("/^(Add|Remove)$/", $displayType)) // (hitting <enter> within the 'userGroupName' text entry field will act as if the user clicked the 'Add' button)
			{
				modifyUserGroups($tableUsers, $displayType, $recordSerialsArray, "", $userGroup); // add (remove) selected records to (from) the specified user group (function 'modifyUserGroups()' is defined in 'include.inc.php')
			}
			elseif (preg_match("/^(Allow|Disallow)$/", $displayType))
			{
				if ($displayType == "Allow")
					$userPermissionsArray = array("$userPermission" => "yes");
				else // ($displayType == "Disallow")
					$userPermissionsArray = array("$userPermission" => "no");

				// Update the specified user permission for the current user:
				$updateSucceeded = updateUserPermissions($recordSerialsArray, $userPermissionsArray); // function 'updateUserPermissions()' is defined in 'include.inc.php'

				if ($updateSucceeded) // save an informative message:
					$HeaderString = returnMsg("User permission $userPermission was updated successfully!", "", "", "HeaderString"); // function 'returnMsg()' is defined in 'include.inc.php'
				else // return an appropriate error message:
					$HeaderString = returnMsg("User permission $userPermission could not be updated!", "warning", "strong", "HeaderString");
			}
		}


		// re-assign the correct display type if the user clicked the 'Add', 'Remove', 'Allow' or 'Disallow' button of the 'queryResults' form:
		$displayType = $originalDisplayType;

		// re-apply the current sqlQuery:
		$query = preg_replace("/ FROM $tableUsers/i",", user_id FROM $tableUsers",$sqlQuery); // add 'user_id' column (which is required in order to obtain unique checkbox names)

		return array($query, $displayType);
	}

	// --------------------------------------------------------------------

	// DISPLAY THE HTML FOOTER:
	// call the 'showPageFooter()' and 'displayHTMLfoot()' functions (which are defined in 'footer.inc.php')
	if (!preg_match("/^(Print|Mobile)$/i", $viewType)) // Note: we omit the visible footer in print/mobile view! ('viewType=Print' or 'viewType=Mobile')
		showPageFooter($HeaderString);

	displayHTMLfoot();

	// --------------------------------------------------------------------
?>