//Adds a bit to z-index of the element and to every parent
Element.addMethods({
	elevate: function(elem, options){
		var conf = {
			altitude:25,
			stopAfter:-1	//maximum iterations, negative values means: go as far as possible
		};
		Object.extend(conf,options || {});		
		elem.setStyle({
			zIndex: parseInt(elem.getStyle("z-index") || 0) + conf.altitude
		});
		conf.stopAfter--;
		return elem !== document.body && (conf.stopAfter!==0)? elem.up().elevate(conf) : elem;
	}
});