function change(id,color)
  {
    document.getElementById(id).style.backgroundImage = "url(optic/menue_left_bg_" + color + "_a.jpg)";
  }

  function changeback(id,color)
  {
    document.getElementById(id).style.backgroundImage = "url(optic/menue_left_bg_" + color + ".jpg)";
  }



  function setLayer(layer) 
  {
	document.getElementById(layer).style.display = 'block';
  }

  function clearLayer(layer)
  {
	document.getElementById(layer).style.display = 'none';
  }