function uhr(stunde_vorher,minute_vorher) 
{
  jetzt = new Date();
  stunde = jetzt.getHours();
  minute = jetzt.getMinutes(); 
 
  document.getElementsByName( "h"+Math.floor((stunde_vorher%12)*5) )[0].style.visibility  = "hidden";     
  document.getElementsByName( "m"+minute_vorher )[0].style.visibility  = "hidden";    

  document.getElementsByName( "h"+Math.floor((stunde%12)*5) )[0].style.visibility  = "visible";     
  document.getElementsByName( "m"+minute )[0].style.visibility  = "visible";    

  setTimeout("uhr("+stunde+","+minute+")", 1000); 
}