function showLayer(layerName) {
            if (document.getElementById) {
                var targetElement = document.getElementById(layerName);
                targetElement.style.visibility = 'visible';
            }
        }


        function hideLayer(layerName) {
            if (document.getElementById) {
                var targetElement = document.getElementById(layerName);
                targetElement.style.visibility = 'hidden';
            }
        }

		var popUp = null;
		var chasm = screen.availWidth;
		var mount = screen.availHeight;
		var w = 0;
		var h = 0;
		function openWindow(url,w,h) {
		
		popUp = window.open(url,'','width=' + w + ',height=' + h + ',left=' + ((chasm - w - 10) * .5) + ',top=' + ((mount - h - 30) * .5));
		}