var isns4 = ((navigator.appName == "Netscape") && (navigator.appVersion.indexOf("4") == 0));

// make the specified layer visible
function showLayer(layerID) {
	obj = getObj(layerID);
	if (obj) {
		if (isns4) {
			obj.visibility = "visible";
		} else {
			obj.style.visibility = "visible";
		}
	}
}

// make the specified layer hidden
function hideLayer(layerID) {	
	obj = getObj(layerID);
	if (obj) {
		if (isns4) {
			obj.visibility = "hidden";
		} else {
			obj.style.visibility = "hidden";
		}
	}
}

// find an object by its name and return it
function getObj(_name, _doc) {
	var p,i,x;
	if(!_doc) {
		_doc=document; 
	}
	if((p=_name.indexOf("?"))>0 && parent.frames.length) {
		_doc=parent.frames[_name.substring(p+1)].document; 
		_name=_name.substring(0,p);
	}
	if(!(x=_doc[_name]) && _doc.all) {
		x=_doc.all[_name];
	}
	if(!x && _doc.anchors) {
		x=_doc.anchors[_name];
	}
	for (i=0;!x && i<_doc.forms.length;i++) {
		x=_doc.forms[i][_name];
	}
	if(!x && _doc.getElementById) {
		x=_doc.getElementById(_name);
	}
	for (i=0;!x && _doc.layers && i<_doc.layers.length;i++) {
		x=findObject(_name,_doc.layers[i].document);
	}
	return x;
}