var RequestABidImageRotator = 
{
  NUMBER_OF_IMAGES : new Number(3),

  init : function()
  {
    var requestABid = $("requestBid");
    requestABid.addClassName("_" + Math.ceil(RequestABidImageRotator.NUMBER_OF_IMAGES*Math.random()));
    return;
  }
}
Event.observe(window, 'load', RequestABidImageRotator.init, false);