function toggleLayer(layer) {
	var layers = new Array("Layer1","Layer2","Layer3","Layer4","Layer5","Layer6","Layer7","Layer8","Layer9");
	for(i=0; i<layers.length; i++){
		if (document.getElementById(layers[i])) {
			var elem = document.getElementById(layers[i]);
			if (layer == layers[i]) {
				elem.style.display = 'block';
			} else {
				elem.style.display = 'none';
			}
		}
	}
}