/*
This work is licensed under the Creative Commons Attribution License.
To view a copy of this license, visit http://creativecommons.org/licenses/by/2.0/
2004 Björn Graf, bjoern.graf@gmx.net, http://b-cage.net/
*/
 
var _preloaded = null;
function preload(preload) {
	_preloaded = [];
	for(var i = 0, l = preload.length; i < l; i++) {
		_preloaded[i] = document.createElement("img");
		_preloaded[i].src = preload[i];
	}
}

function swapImg(evt, newImg, imgId) {
	var dst = imgId ? document.getElementById(imgId) : (evt.srcElement || evt.target);
	dst.src = typeof(newImg) == "number" ? _preloaded[newImg].src : newImg;
}