function DivEinAusblenden(divName)
{
 if(document.getElementById(divName))
 {
   if(document.getElementById(divName).style.display == 'none')
   {
    document.getElementById(divName).style.display = 'block';
  }
  else
  {
    document.getElementById(divName).style.display = 'none';
  }
 }
}