function showtopdd(elmnt)	
	{ 
	if (document.layers)
	  { document.layers[elmnt].visibility="show"; }
	if (document.all)
	  { document.all[elmnt].style.visibility="visible"; }
	else
	  { document.getElementById(elmnt).style.visibility="visible"; }
	}

function hidetopdd(elmnt)	
	{ 
		if (document.layers)
		{ document.layers[elmnt].visibility="hide"; }
		if (document.all)
		{ document.all[elmnt].style.visibility="hidden"; }
		else
		{ document.getElementById(elmnt).style.visibility="hidden"; }
	}