var PAGEURL;
var oldImg="";

function showLayer(layerName){
	var map=PAGEURL+"kartbilder/"+layerName+".gif";
	document.getElementById("mapHolder").src=map;
	showStn(layerName);
}

function showStn(layerName){
	if(oldImg!=""){
		document.getElementById(oldImg).style.visibility="hidden";	
	}
	document.getElementById(layerName).style.visibility="visible";
	oldImg=layerName;
}