function switchlayer(Layer_Name)
{
  var GECKO = document.getElementById ? 1 : 0 ;
  var NS = document.layers ? 1 : 0 ;
  var IE = document.all ? 1 : 0 ;

  if (GECKO)
{
	   document.getElementById(Layer_Name).style.display = (document.getElementById(Layer_Name).style.display == 'block') ? 'none' : 'block';
	   }
  else if (NS)
       {
	   document.layers(Layer_Name).display = (document.layers(Layer_Name).display == 'block') ? 'none' : 'block';
	   }
  else if (IE)
       {
	   document.all(Layer_Name).style.display = (document.all(Layer_Name).style.display == 'block') ? 'none' : 'block';
	   }
}