var ns4 = (document.layers);
var ie4 = (document.all && !document.getElementById);
var ie5 = (document.all && document.getElementById);
var ns6 = (!document.all && document.getElementById);

function layerObject(id) {
	if (ie5||ns6) {
		this.obj = document.getElementById(id).style;
		return this.obj;
	}
	else if(ie4) {
		this.obj = document.all[id].style;
		return this.obj;
	}
	else if(ns4) {
		this.obj = document.layers[id];
		return this.obj;
	}
}

function shownav(lay) {
	if (ie4) {
		document.all.msf.style.visibility = "hidden";
		document.all.msc.style.visibility = "hidden";
		document.all.mhe.style.visibility = "hidden";
		document.all.mos.style.visibility = "hidden";
		document.all[lay].style.visibility = "visible";
	}
	if (ns4) {
		document.layers.msf.visibility = "hide";
		document.layers.msc.visibility = "hide";
		document.layers.mhe.visibility = "hide";
		document.layers.mos.visibility = "hide";
		document.layers[lay].visibility = "show";
	}
	if (ns6||ie5) {
		document.getElementById('msf').style.display = "none";
		document.getElementById('msc').style.display = "none";
		document.getElementById('mhe').style.display = "none";
		document.getElementById('mos').style.display = "none";
		document.getElementById([lay]).style.display = "block";
	}
}