function showlayer(layer){
		var currLayer = document.getElementById(layer).style.display;
		if(currLayer=="none"){
			document.getElementById(layer).style.display="block";
		} else { 
			document.getElementById(layer).style.display="none";
		}
	}
	function openPopWindow(theURL,winName,features) { 
  		window.open(theURL,winName,features);
	}