Protoload = {
	timeUntilShow: 250,
	opacity: 0.8,
	startWaiting: function(element, className, timeUntilShow) {
		if (typeof element == 'string')
			element = document.getElementById(element);
		if (className == undefined)
			className = 'waiting';
		if (timeUntilShow == undefined)
			timeUntilShow = Protoload.timeUntilShow;
		element._waiting = true;
		if (!element._loading) {
			var e = document.createElement('div');
			(element.offsetParent || document.body).appendChild(element._loading = e);
			e.style.position = 'absolute';
			try {e.style.opacity = Protoload.opacity;} catch(e) {}
			try {e.style.MozOpacity = Protoload.opacity;} catch(e) {}
			try {e.style.filter = 'alpha(opacity='+Math.round(Protoload.opacity * 100)+', style=0)';} catch(e) {}
			try {e.style.KhtmlOpacity = Protoload.opacity;} catch(e) {}
		}
		element._loading.className = className;
		window.setTimeout((function() {
			if (this._waiting) {
				var left = this.offsetLeft, 
					top = this.offsetTop,
					width = this.offsetWidth,
					height = this.offsetHeight,
					l = this._loading;
					l.style.left = left+'px';
					l.style.top = top+'px';
					l.style.width = width+'px';
					l.style.height = height+'px';
					l.style.display = 'inline';
			}
		}).bind(element), timeUntilShow);
	},
	stopWaiting: function(element) {
		if (element._waiting) {
			element._waiting = false;
			element._loading.parentNode.removeChild(element._loading);
			element._loading = null;
		}
	}
};

if (Prototype) {
	Element.addMethods(Protoload);
	Object.extend(Element, Protoload);
}