diff --git a/ag/include/usergroup.inc.php b/ag/include/usergroup.inc.php
index 458c1f3..601ceae 100644
--- a/ag/include/usergroup.inc.php
+++ b/ag/include/usergroup.inc.php
@@ -8,6 +8,7 @@
 
 include_once (ROOT_PATH . '/include/defines.inc.php');
 include_once(ROOT_PATH.'/include/parse.inc.php');
+include_once(ROOT_PATH.'/include/sqlwrapper.inc.php');
 
 //Konstanten
 defineIfNotDefined('ADMIN', 1);
@@ -28,13 +29,13 @@ function getUserGroups($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);
+		$qry = db_query($test);
 	} else if (validateString($user) != null) {
 		$test = 'SELECT ug.gruppen_name, ug.gruppen_id FROM user_gruppe_zuordnung as ugz
 							INNER JOIN user_gruppe as ug ON ugz.gruppen_id=ug.gruppen_id
 							INNER JOIN user as u ON u.id=ugz.user_id
 							WHERE u.nickname = \''.$user.'\'';
-		$qry = mysql_query($test);
+		$qry = db_query($test);
 	}
 
 	$i = 0;
@@ -46,6 +47,9 @@ function getUserGroups($user) {
 }
 
 function isUserInGroup(array $usergrouparray, $group) {
+	if($group == null || count($usergrouparray) == 0 || $usergrouparray == null) {
+		return false;
+	}
 	for($i = 0; $i < count($usergrouparray); $i++) {
 		if($usergrouparray[$i]['gruppen_id'] == $group) {
 			return true;
@@ -59,7 +63,7 @@ function removeUserFromGroup($user, $group) {
 		if ($group !== NULL && $group >= 0) {
 			$qry = 'DELETE FROM user_gruppe_zuordnung WHERE user_id in (SELECT id FROM user WHERE nickname = \''.$user.
 			'\') AND gruppen_id = '.$group.';';
-			mysql_query($qry);
+			db_query($qry);
 			return true;
 		}
 	}
@@ -71,7 +75,7 @@ function addUserToGroup($user, $group) {
 		if ($group !== NULL && $group >= 0) {
 			$qry = 'INSERT INTO user_gruppe_zuordnung(user_id, gruppen_id)
 			VALUES((SELECT id FROM user WHERE nickname = \''.$user.'\'), '.$group.');';
-			mysql_query($qry);
+			db_query($qry);
 			return true;
 		}
 	}