Array.prototype.contains = function(obj) {//Hilfsfunktion zur Element-Abfrage eines Arrays
 for(var i=0; i<this.length; i++) {
  if (this[i].toLowerCase()==obj.toLowerCase()) return true;
 }
 return false;
}

function vkalenderRubrikAuswahl(drp_id, tab_id) { 
 var drp = document.getElementById(drp_id);
 var kal = document.getElementById(tab_id); 
 var thm = drp.options[drp.selectedIndex].value.toLowerCase();
 if (thm == "") return false;
 if (thm == "all") {
  for (var i =1; i < kal.rows.length; i++) {
   try {
    kal.getElementsByTagName("tr")[i].style.display="table-row";
   } catch(err) { 
    kal.getElementsByTagName("tr")[i].style.display="block";
   }
  }
 } else {
  for (var i = 1; i < kal.rows.length; i++) {//alle tr durchlaufen und ein/ausblenden
   var tr_id=kal.rows[i].getAttribute("id").toLowerCase();//id der tr auslesen
   var tr_id_arr = tr_id.split("_");
 //if (tr_id == thm) {
   if(tr_id_arr.contains(thm)){
    try {
     kal.getElementsByTagName("tr")[i].style.display="table-row";
    } catch(err) { 
     kal.getElementsByTagName("tr")[i].style.display="block";
    }
   } else {
    kal.getElementsByTagName("tr")[i].style.display="none"; 	
   }
  } 
 }
}