var W3CDOM = (document.createElement && document.getElementsByTagName);

var mouseOvers = new Array();
var mouseOuts = new Array();

window.onload = init;

document.getElementsByClassName = function(className) {
  var children = document.getElementsByTagName('*') || document.all;
  var elements = new Array();
  
  for (var i = 0; i < children.length; i++) {
    var child = children[i];
    var classNames = child.className.split(' ');
    for (var j = 0; j < classNames.length; j++) {
      if (classNames[j] == className) {
        elements.push(child);
        break;
      }
    }
  }
  return elements;
}

function init()
{
	if (!W3CDOM) return;

	var imgs = document.getElementsByClassName('mouseover');
	for (var i=0;i<imgs.length;i++)
	{
		imgs[i].onmouseover = mouseGoesOver;
		imgs[i].onmouseout = mouseGoesOut;
		var suffix = imgs[i].src.substring(imgs[i].src.lastIndexOf('.'));
		mouseOuts[i] = new Image();
		mouseOuts[i].src = imgs[i].src;
		mouseOvers[i] = new Image();
		mouseOvers[i].src = imgs[i].src.substring(0,imgs[i].src.lastIndexOf('.')) + "_f2" + suffix;
		imgs[i].number = i;
	}
}

function mouseGoesOver()
{
	this.src = mouseOvers[this.number].src;
}

function mouseGoesOut()
{
	this.src = mouseOuts[this.number].src;
}