dom.event.addEventListener(window, 'load', hoverInit);

function hoverInit(){
  var preloads = new Array();
  var images = document.getElementsByTagName("img");
  for(var i = 0; i < images.length; i++){
		switch(images.item(i).className){
			case('hover'):
	      var src = images.item(i).getAttribute('src');
	      var ftype = src.substring(src.lastIndexOf('.'), src.length);
	      var hoversrc = src.replace(ftype, '_on'+ftype);
	      images.item(i).setAttribute('tempsrc', src);
	      images.item(i).setAttribute('hoversrc', hoversrc);
	
	      preloads[i] = new Image();
	      preloads[i].src = hoversrc;
	
	
	      dom.event.addEventListener(images.item(i), 'mouseover', hover);
	      dom.event.addEventListener(images.item(i), 'mouseout', out);
			default:
				break;
		}
  }
}


function hover(evt){
  var target = dom.event.target(evt);
  target.setAttribute('src', target.getAttribute('hoversrc'));
}


function out(evt){
  var target = dom.event.target(evt);
  target.setAttribute('src', target.getAttribute('tempsrc'));
}