if (document.images)
   {
     cutshotcover= new Image(150,200);
     cutshotcover.src="images/cutshotcover_unisized.gif";

     snaphookcover= new Image(150,200);
     snaphookcover.src="images/snaphookcover_unisized.gif";
     
     centercutcover= new Image(150,200);
     centercutcover.src="images/centercutcover_unisized.gif";
    
     badliecover= new Image(150,200);
     badliecover.src="images/badliecover_unisized.gif";
   }

function turnon(cover)
 {
   if (document.images)
    {
      document['bookcover'].src= eval(cover + ".src");
    }
 }