if (document.images)
  {	
     b1_lo = new Image();b1_lo.src="images/contact_b.gif";
     b1_hi = new Image();b1_hi.src="images/contact_hi.gif";
     b2_lo = new Image();b2_lo.src="images/home_b.gif";
     b2_hi = new Image();b2_hi.src="images/home_hi.gif";	
     b3_lo = new Image();b3_lo.src="images/about_b.gif";
     b3_hi = new Image();b3_hi.src="images/about_hi.gif";	  
     b4_lo = new Image();b4_lo.src="images/auction_b.gif";
     b4_hi = new Image();b4_hi.src="images/auction_hi.gif";	 
  }
function Roll(e,im)
 {
  e.src=im.src;
 }