className = 'swap';
imgOverName = '_Over';
imgDownName = '_Down';
Event.observe(window, 'load', imgSwap, false);
function imgSwap()
{
	var btns = $A(document.getElementsByClassName(className));
	btns.each(
		function (node)
		{
			node.img = node.src;
			node.imgOver = node.src.replace('.gif', imgOverName + '.gif').replace('.png', imgOverName + '.png').replace('.jpg', imgOverName + '.jpg');
			node.imgDown = node.src.replace('.gif', imgDownName + '.gif').replace('.png', imgDownName + '.png').replace('.jpg', imgDownName + '.jpg');
			node.onmouseover =
				function()
				{
					this.src = this.imgOver;
				};
			node.onmouseout = node.onmouseup =
				function()
				{
					this.src = this.img;
				};
			node.onmousedown =
				function()
				{
					this.src = this.imgDown;
				};
		}
	);
}