var isNav, isIE;

if (parseInt(navigator.appVersion) >= 4) {
	if (navigator.appName.indexOf("Netscape")>=0)
		isNav = true;
	else if (navigator.appName.indexOf("Internet Explorer")>=0)
		isIE = true;
}

if (window._ro == null) {
	// Only set this up once per page
	window._ro = 1;
	pImages = new Object();
}


function newImage(url) {
	if (document.images) {
		var img = new Image();
		img.src = url;
		return img;
	}
}

function RolloverImg(normal, over) {
	this.normal = newImage(normal);
	this.over = newImage(over);
	this.enabled=true;
}

function setupRollover(name, normal, over) {
	if (document.images) {
		var rimg = pImages[name];
		if (rimg == null) {
			rimg = new RolloverImg(normal,over);
			pImages[name] = rimg;
		} else {
			rimg.normal.src = normal;
			rimg.over.src = over;
		}
	}
}

function setEnabled(name, enabled) {
	var rimg=pImages[name];
	if (rimg)
		pImages[name].enabled=enabled;
}

function setRollState() {
	
	if (document.images) {
		for (var i=0; i<setRollState.arguments.length; i+=2) {
			var name = setRollState.arguments[i];
			var state = setRollState.arguments[i+1];
			var elm = document[name];
			var rimg = pImages[name];
			
			if (elm && rimg) {
				
				if ((state == 0) || (!rimg.enabled)) {
					var img = rimg.normal;
				} else {
					var img = rimg.over;
				}
				if (img) {
					elm.src = img.src;
				}
				
			}
		}
	}
	return true;
}