// VIEW LAYERS
var cur_lyr;	// holds id of currently visible layer
var cur_lyr2;	// holds id of currently visible layer2
function swapLayers(id) {
	if (cur_lyr) hideLayer(cur_lyr);
	showLayer(id);
	cur_lyr = id;
}
// SHOWS THE LAYER WITHOUT HIDING ALL OTHER LAYERS
function swapLayers2(id) {
	if (cur_lyr2) hideLayer(cur_lyr2);
	showLayer(id);
	cur_lyr2 = id;
}
// SHOWS THE LAYER WITHOUT HIDING ALL OTHER LAYERS
function swapLayers3(id) {
	if (cur_lyr3) hideLayer(cur_lyr3);
	showLayer(id);
	cur_lyr3 = id;
}
function showLayer(id) {
	var lyr = getElemRefs(id);
	if (lyr && lyr.css) lyr.css.display = "block";
}
function hideLayer(id) {
	var lyr = getElemRefs(id);
	if (lyr && lyr.css) lyr.css.display = "none";
}
function getElemRefs(id) {
	var el = (document.getElementById)? document.getElementById(id): (document.all)? document.all[id]: (document.layers)? document.layers[id]: null;
	if (el) el.css = (el.style)? el.style: el;
	return el;
}