/* props to daniel nolan! */

function rollerDerby() {
	if (!document.getElementById) return
	
	var rollArray = new Array();
	var rollTemp;
	var rollImg = document.getElementsByTagName('img');

	for (var i = 0; i < rollImg.length; i++) {		
		if (rollImg[i].className == 'roller') {
			var rollOld = rollImg[i].getAttribute('src');
			var ext = rollOld.substring(rollOld.lastIndexOf('.'), rollOld.length);
			var rollNew = rollOld.replace(ext, '-ovr'+ext);

			rollImg[i].setAttribute('rollNew', rollNew);
			
			rollArray[i] = new Image();
			rollArray[i].rollOld = rollNew;
			
			rollImg[i].onmouseover = function() {
				rollTemp = this.getAttribute('src');
				this.setAttribute('src', this.getAttribute('rollNew'));
			}	
			
			rollImg[i].onmouseout = function() {
				if (!rollTemp) rollTemp = this.getAttribute('src').replace('-ovr'+ext, ext);
				this.setAttribute('src', rollTemp);
			}
		}
	}
}

window.onload = rollerDerby;