+function check_vacation($userid)
+{
+ /* get start date */
+ $result = DB_query_array("SELECT value FROM User_Prefs".
+ " WHERE user_id='$userid' AND pref_key='vacation start'" );
+ if($result)
+ $start = $result[0];
+ else
+ return NULL;
+
+ /* get end date */
+ $result = DB_query_array("SELECT value FROM User_Prefs".
+ " WHERE user_id='$userid' AND pref_key='vacation stop'" );
+ if($result)
+ $stop = $result[0];
+ else
+ return NULL;
+
+ /* get comment */
+ $result = DB_query_array("SELECT value FROM User_Prefs".
+ " WHERE user_id='$userid' AND pref_key='vacation comment'" );
+ if($result)
+ $comment = $result[0];
+ else
+ $comment = '';
+
+ /* check if user is on vacation. TODO: use user's timezone */
+ if( (time() - strtotime($start) >0) &&
+ (strtotime($stop) - time() >0))
+ return array ($start,$stop,$comment);
+ else
+ return NULL;
+}