ns = (document.layers)? true:false        
ie = (document.all)? true:false           

function show(show_div)
{
if (ie)
   {
     	Layer1.style.visibility='hidden';
   	Layer2.style.visibility='hidden';
   	Layer3.style.visibility='hidden';
   	Layer4.style.visibility='hidden';
   	Layer7.style.visibility='hidden';
	document.all[show_div].style.visibility='visible';
   }
if (ns)
   {
   	document.Layer1.visibility='hide';
	document.Layer2.visibility='hide';
   	document.Layer3.visibility='hide';
   	document.Layer4.visibility='hide';
	document.Layer7.visibility='hide';
	document.layers[show_div].visibility='show'
	}
}
function hidediv()
{
if (ie)
   {
     Layer1.style.visibility='hidden';
   	Layer2.style.visibility='hidden';
	Layer3.style.visibility='hidden';
	Layer4.style.visibility='hidden';
	Layer7.style.visibility='hidden';
   }
if (ns)
   {
   //alert('Layer1 in_ns is ok');
   	document.Layer1.visibility='hide';
	document.Layer2.visibility='hide';
	document.Layer3.visibility='hide';
	document.Layer4.visibility='hide';
	document.Layer7.visibility='hide';
   }
}