function showForm(id)
{
    if(document.getElementById(id).style.display == "block")
    {
      document.getElementById(id).style.display = "none";
      document.getElementById(id).style.visibility = "hidden";
    }
    else
    {    
      document.getElementById(id).style.display = "block";
      document.getElementById(id).style.visibility = "visible";
    }
}


function bildwechsel()
{
  bildwechsel.counter++;

  if(bildwechsel.counter == 11)
    bildwechsel.counter = 1;
  
  document.toplogo.src=bild[bildwechsel.counter].src;
  window.setTimeout("bildwechsel()",3000);
}