if (document.images) 
{
      img1 = new Image();
      img2 = new Image();
      img3 = new Image();
      img1.src ="http://voidmedia.com.au/template/blots/js/images/button-continue-over.png"; 
      img2.src ="http://voidmedia.com.au/template/blots/js/images/button-quote-over.png";  
      img3.src ="http://voidmedia.com.au/template/blots/js/images/button-submit-over.png"; 
}