function setrollovers() {
	var myImage = function(image){
		if (image.className != "over" && image.className != "setover"){
			return;
		}
		
		var src = image.getAttribute('src');
		var preLoad = new Image();
		if (image.className == "over"){
			var type = src.substring(src.lastIndexOf('.'));
			preLoad.src = src.replace(type, '_ovr' + type)
		} else {
			preLoad.src = image.getAttribute("over");
		}

		image.onmouseover = function(){
			this.src = preLoad.src;
		}
		
		image.onmouseout = function(){
			this.src = src;
		}
	}

	var images = document.getElementsByTagName('img');
	for (var i = 0; i < images.length; i++) {
		myImage(images[i]);
	}
}

function myonload(){
	setrollovers();
}

window.onload = myonload;