function initRollovers() {
	if (!document.getElementById) return;
	
	var aPreLoad = new Array();
	var sTempSrc;
	var aImages = document.getElementsByTagName('img');

	for(var i = 0; i < aImages.length; i++) {
		if(aImages[i].className == 'rollover') {
			var src = aImages[i].getAttribute('src');
			var extension = src.substring(src.lastIndexOf('.'), src.length);
			var hsrc = src.replace(extension, '_over' + extension);

			aImages[i].setAttribute('hsrc', hsrc);
			
			aPreLoad[i] = new Image();
			aPreLoad[i].src = hsrc;
			
			aImages[i].onmouseover = function() {
				sTempSrc = this.getAttribute('src');
				this.setAttribute('src', this.getAttribute('hsrc'));
			}
			
			aImages[i].onmouseout = function() {
				if (!sTempSrc) sTempSrc = this.getAttribute('src').replace('_o' + extension, extension);
				this.setAttribute('src', sTempSrc);
			}
		}
	}
}

addLoadEvent(initRollovers);