NS4 = (document.layers) ? 1 : 0;
IE4 = (document.all) ? 1 : 0;
ver4 = (NS4 || IE4) ? 1 : 0;

function Replace(Name, Source) 
{
   if (ver4 == true) 
   {    
	  document[Name].src = Source ;				
   }

   return true;

}

             
 	
function popUp(chunk,on, top,left) 
{
	if (ver4)
	{
		if (on) 
		{				
	
			if (NS4) 
			{	
				document.layers[chunk].left = left;
				document.layers[chunk].top = top;
				document.layers[chunk].visibility = "show";
			}
			else
			{
				document.all[chunk].style.pixelLeft = left;
				document.all[chunk].style.pixelTop =  top;
				document.all[chunk].style.visibility = "visible";
		        }
 		}
		else
		{
			if (NS4) 
			{
				document.layers[chunk].visibility = "hide";
			}
			else
			{
				document.all[chunk].style.visibility = "hidden";
			}
		}
	}
}