Event.observe(window, "load", initPrototypeRollovers);

function initPrototypeRollovers(e)
{
  var imgs = $$('img.proto_rollover');
  if(imgs.length>0)
  {
    var i = 0;
    for(i=0;i<imgs.length;i++)
    {
      Event.observe(imgs[i], "mouseover", pr_over);
      Event.observe(imgs[i], "mouseout", pr_out);
    }
  }
}

function pr_over(e)
{
  var img = Event.element(e);
  if(img && img.src)
  {
    var filepath = img.src.split("/");
    var filename = filepath[filepath.length-1];
    var file = filename.split(".");
    if(file.length==2)
    {
      file[0] = file[0] + "_on";
      filename = file.join(".");
      filepath[filepath.length-1] = filename;
      img.src = filepath.join("/");
    }
    
  }
}

function pr_out(e)
{
  var img = Event.element(e);
  if(img && img.src)
  {
    var filepath = img.src.split("/");
    var filename = filepath[filepath.length-1];
    var file = filename.split(".");
    if(file.length==2)
    {
      file[0] = file[0].replace("_on", "");
      filename = file.join(".");
      filepath[filepath.length-1] = filename;
      img.src = filepath.join("/");
    }
    
  }
}