var navTimeout=0;
var active=false;

var nBrowserVersion=parseInt(navigator.appVersion);
var sBrowserName=navigator.appName;
var bIE4=((document.all) && (nBrowserVersion >= 4) && (!window.opera)) ? true : false;

if (bIE4){
	var sNavLayerSuffix="nav";
	var nCurrNum=null;
}

function fnLayerName(sSuffix, nNum){
	return sSuffix+nNum;
}

if (bIE4){
	var layerRef="document.all['";
	var styleSwitch="'].style";
	var sOn=".visibility=\"visible\"";
	var sOff=".visibility=\"hidden\"";
}

function fnSetStyle(sLayerName, sStyle){
	eval(layerRef+sLayerName+styleSwitch+sStyle);
}

function getOffsetLeft(obj){
	var tmp = obj.offsetLeft;
	while (obj.offsetParent != null){
		obj = obj.offsetParent;
		tmp += obj.offsetLeft;
		if (obj.tagName == "BODY") break;
	}
	return tmp;
}

function getOffsetTop(obj){
	var tmp = obj.offsetTop;
	while (obj.offsetParent != null){
		obj = obj.offsetParent;
		tmp += obj.offsetTop;
		if (obj.tagName == "BODY") break;
	}
	return tmp;
}

function layer_on(obj, nNum){
//alert(isLoaded);
	if (navTimeout) return;
	var sLeft="";
	var sTop="";
	if ((bIE4)&&(isLoaded)){
		if (nCurrNum!=null) layer_off(nCurrNum);
		sCurrLayer = fnLayerName(sNavLayerSuffix, nNum);
		if (obj){
			fullLeft=getOffsetLeft(obj)-15;
			if (nNum == "0") fullLeft-=5;
			sLeft=".left=\""+fullLeft+"\"";
			fullTop=getOffsetTop(obj)+obj.offsetHeight-5;
			sTop=".top=\""+fullTop+"\"";
			fnSetStyle(sCurrLayer, sLeft);
			fnSetStyle(sCurrLayer, sTop);
		}
		fnSetStyle(sCurrLayer, sOn);
		nCurrNum=nNum;
	}

}

function do_layer_on(nNum){
	active=true;
	sCurrLayer = fnLayerName(sNavLayerSuffix, nNum);
	fnSetStyle(sCurrLayer, sOn);
}

function do_layer_off(nNum){
	active=false;
	sCurrLayer = fnLayerName(sNavLayerSuffix, nNum);
	fnSetStyle(sCurrLayer, sOff);
}

function layer_off(nNum){
	if (bIE4 && isLoaded){
		sCurrLayer = fnLayerName(sNavLayerSuffix, nNum);
		fnSetStyle(sCurrLayer, sOff);
	}
}