var isActive = "";

function switchPic (id, src) {
	document.getElementById(id).src = src;
}

function toogleLayer(layerName) {

		if (document.getElementById(layerName).style.display == "block") {
			document.getElementById(layerName).style.display = "none";
			isActive = "";
		}
		else {
			if (isActive != "") {
				document.getElementById(isActive).style.display = "none";
			}
			document.getElementById(layerName).style.display = "block";
			isActive = layerName;
		}
		
}