namen = new Array("Montag","Dienstag","Mittwoch","Donnerstag","Freitag","Samstag","Sonntag");

function test(text){
   for(i=0;i<7;i++){
   var texty = text.substring(0,2).toLowerCase();
   var namy = namen[i].substring(0,2).toLowerCase();
   if(texty == namy){
  document.getElementById("hugo").value =namen[i];
    }
   }
 }