diff --git a/ag/gm/gm_seite.php b/ag/gm/gm_seite.php
index b386964..74438b2 100644
--- a/ag/gm/gm_seite.php
+++ b/ag/gm/gm_seite.php
@@ -68,14 +68,15 @@ function loginUser($user,$pass){
 		$result = mysql_fetch_assoc($qry);		
 		$usergroups = getUserGroups($user);
 				
-		if(isUserInGroup($usergroups, Admin)) {
+		if(isUserInGroup($usergroups, admin)) {
 			$_SESSION['user'] = $result['id'];
 			$_SESSION['username'] = $result['nickname'];
 			$_SESSION['password'] = $result['passwort'];
 			$_SESSION['usergroups'] = $usergroups;
 			echo '<a href="'.$_SERVER['PHP_SELF'].'">Zum Hauptmenu</a>';		
+			return true;
 		}
-		return true;
+		return false;
 	}
 	echo displayHistoryBackLink();
 	return false;
diff --git a/ag/gm/include/user.inc.php b/ag/gm/include/user.inc.php
index 37aa2ad..9450f15 100644
--- a/ag/gm/include/user.inc.php
+++ b/ag/gm/include/user.inc.php
@@ -15,20 +15,20 @@ function getOtherUserGroups($user) {
 	$groups = array();
 
 	//prüfen welcher wert für user steht (id oder name)
-	if(validateInteger($user, null) != null) {
-		$test = 'SELECT gruppe_id, gruppe_name FROM user_gruppe WHERE gruppe_id not in
-				(SELECT gruppe_id FROM user_gruppe_zuordnung WHERE user_id = \''.$user.'\')';
+	if(is_numeric($user)) {
+		$test = 'SELECT gruppen_id, gruppen_name FROM user_gruppe WHERE gruppen_id not in
+				(SELECT gruppen_id FROM user_gruppe_zuordnung WHERE user_id = \''.$user.'\')';
 		$qry = mysql_query($test);
 	} else if (validateString($user) != null) {
-		$test = 'SELECT gruppe_id, gruppe_name FROM user_gruppe WHERE gruppe_id not in
-				(SELECT ugz.gruppe_id FROM user u INNER JOIN user_gruppe_zuordnung ugz ON
+		$test = 'SELECT gruppen_id, gruppen_name FROM user_gruppe WHERE gruppen_id not in
+				(SELECT ugz.gruppen_id FROM user u INNER JOIN user_gruppe_zuordnung ugz ON
 				 u.id=ugz.user_id WHERE nickname = \''.$user.'\')';
 		$qry = mysql_query($test);
 	}
 
 	$i = 0;
 	while ($result = mysql_fetch_assoc($qry)) {
-		$groups[$i] = array("gruppe_id" => $result['gruppe_id'], "gruppe_name" => $result['gruppe_name']);
+		$groups[$i] = array("gruppen_id" => $result['gruppen_id'], "gruppen_name" => $result['gruppen_name']);
 		$i++;
 	}
 
@@ -40,10 +40,10 @@ function displayUserGroups($action, $name, $ugname, $delete, $add) {
 		$username = validateName($name);
 		if ($delete !== NULL && $delete >= 0) {
 			$qry = 'DELETE FROM user_gruppe_zuordnung WHERE user_id in (SELECT id FROM user WHERE nickname = \''.$username.
-			'\') AND gruppe_id = '.$delete.';';
+			'\') AND gruppen_id = '.$delete.';';
 			mysql_query($qry);
 		} else if($add !== NULL && $add >= 0) {
-			$qry = 'INSERT INTO user_gruppe_zuordnung(user_id, gruppe_id)
+			$qry = 'INSERT INTO user_gruppe_zuordnung(user_id, gruppen_id)
 			VALUES((SELECT id FROM user WHERE nickname = \''.$username.'\'), '.$add.');';
 			mysql_query($qry);
 		}
@@ -65,7 +65,7 @@ function displayUserGroups($action, $name, $ugname, $delete, $add) {
 					<option value="-1">Gruppe ausw&auml;hlen</option>
 					<?php
 					for($i = 0; $i < count($usergroups); $i++) {
-						echo '<option value="'.$usergroups[$i]['gruppe_id'].'">'.$usergroups[$i]['gruppe_name'].'</option>';
+						echo '<option value="'.$usergroups[$i]['gruppen_id'].'">'.$usergroups[$i]['gruppen_name'].'</option>';
 					}
 					?>
 			</select> <input type="submit" value="löschen" />
@@ -76,7 +76,7 @@ function displayUserGroups($action, $name, $ugname, $delete, $add) {
 					<option value="-1">Gruppe ausw&auml;hlen</option>
 					<?php
 					for($i = 0; $i < count($notusergroups); $i++) {
-						echo '<option value="'.$notusergroups[$i]['gruppe_id'].'">'.$notusergroups[$i]['gruppe_name'].'</option>';
+						echo '<option value="'.$notusergroups[$i]['gruppen_id'].'">'.$notusergroups[$i]['gruppen_name'].'</option>';
 					}
 					?>
 			</select> <input type="submit" value="hinzufügen" />
@@ -89,7 +89,7 @@ function displayUserGroups($action, $name, $ugname, $delete, $add) {
 						<th>Usergruppen</th>
 						<?php
 						for($i = 0; $i < count($usergroups); $i++) {
-							echo '<tr><td align="center">'.$usergroups[$i]['gruppe_name'].'</td>';
+							echo '<tr><td align="center">'.$usergroups[$i]['gruppen_name'].'</td>';
 						}
 						?>
 				
@@ -112,8 +112,8 @@ function displayUserGroups($action, $name, $ugname, $delete, $add) {
 	} else if($action === 'show') {
 		$username = validateName($ugname);
 		$sqlqry = 'SELECT u.nickname FROM user_gruppe_zuordnung ugz
-					INNER JOIN user_gruppe ug ON ug.gruppe_id=ugz.gruppe_id
-					INNER JOIN user u ON ugz.user_id=u.id WHERE ug.gruppe_name = \''.$ugname.'\';';
+					INNER JOIN user_gruppe ug ON ug.gruppen_id=ugz.gruppen_id
+					INNER JOIN user u ON ugz.user_id=u.id WHERE ug.gruppen_name = \''.$ugname.'\';';
 		$usergroups_qry = mysql_query($sqlqry);
 		?>
 <table width="80%">
@@ -174,11 +174,11 @@ function displayUserGroups($action, $name, $ugname, $delete, $add) {
 						<th>Usergruppe</th>
 						<th>Beschreibung</th>
 						<?php
-						$usergroups_qry = mysql_query('SELECT gruppe_name, gruppe_beschreibung FROM user_gruppe ug;');
+						$usergroups_qry = mysql_query('SELECT gruppen_name, gruppen_beschreibung FROM user_gruppe ug;');
 						while($row = mysql_fetch_assoc($usergroups_qry)){
 							echo '<tr><td align="center"><a href="'
-							.$_SERVER['PHP_SELF'].'?choose=usergroups&action=show&ugname='.$row['gruppe_name'].'">'
-							.$row['gruppe_name'].'</a></td><td>'.$row['gruppe_beschreibung'].'</td></tr>';
+							.$_SERVER['PHP_SELF'].'?choose=usergroups&action=show&ugname='.$row['gruppen_name'].'">'
+							.$row['gruppen_name'].'</a></td><td>'.$row['gruppen_beschreibung'].'</td></tr>';
 						}
 						?>
 				
diff --git a/ag/include/usergroup.inc.php b/ag/include/usergroup.inc.php
index c28f391..0adb19e 100644
--- a/ag/include/usergroup.inc.php
+++ b/ag/include/usergroup.inc.php
@@ -7,8 +7,8 @@
  */
 
 //Konstanten
-define("Admin", 1);
-define("Tester", 2);
+define("admin", 1);
+define("tester", 2);
 
 include_once($_SERVER['DOCUMENT_ROOT'].'ag/include/parse.inc.php');
 
@@ -17,14 +17,14 @@ function getUserGroups($user) {
 	$groups = array();
 
 	//prüfen welcher wert für user steht (id oder name)
-	if(validateInteger($user, null) != null) {
-		$test = 'SELECT ug.gruppe_name, ug.gruppe_id FROM user_gruppe_zuordnung as ugz
-							INNER JOIN user_gruppe as ug ON ugz.gruppe_id=ug.gruppe_id
+	if(is_numeric($user)) {
+		$test = 'SELECT ug.gruppen_name, ug.gruppen_id FROM user_gruppe_zuordnung as ugz
+							INNER JOIN user_gruppe as ug ON ugz.gruppen_id=ug.gruppen_id
 							WHERE ugz.user_id = \''.$user.'\'';
 		$qry = mysql_query($test);
 	} else if (validateString($user) != null) {
-		$test = 'SELECT ug.gruppe_name, ug.gruppe_id FROM user_gruppe_zuordnung as ugz
-							INNER JOIN user_gruppe as ug ON ugz.gruppe_id=ug.gruppe_id 
+		$test = 'SELECT ug.gruppen_name, ug.gruppen_id FROM user_gruppe_zuordnung as ugz
+							INNER JOIN user_gruppe as ug ON ugz.gruppen_id=ug.gruppen_id 
 							INNER JOIN user as u ON u.id=ugz.user_id 
 							WHERE u.nickname = \''.$user.'\'';
 		$qry = mysql_query($test);
@@ -32,7 +32,7 @@ function getUserGroups($user) {
 
 	$i = 0;
 	while ($result = mysql_fetch_assoc($qry)) {
-		$groups[$i] = array("gruppe_id" => $result['gruppe_id'], "gruppe_name" => $result['gruppe_name']);
+		$groups[$i] = array("gruppen_id" => $result['gruppen_id'], "gruppen_name" => $result['gruppen_name']);
 		$i++;
 	}