if (document.images) {
     button10 = new Image(); button10.src = "images/button10.gif";
     button11 = new Image(); button11.src = "images/button11.gif";
     button20 = new Image(); button20.src = "images/button20.gif";
     button21 = new Image(); button21.src = "images/button21.gif";
     button30 = new Image(); button30.src = "images/button30.gif";
     button31 = new Image(); button31.src = "images/button31.gif";
     button40 = new Image(); button40.src = "images/button40.gif";
     button41 = new Image(); button41.src = "images/button41.gif";
     button50 = new Image(); button50.src = "images/button50.gif";
     button51 = new Image(); button51.src = "images/button51.gif";
     button60 = new Image(); button60.src = "images/button60.gif";
     button61 = new Image(); button61.src = "images/button61.gif";
     button70 = new Image(); button70.src = "images/button70.gif";
     button71 = new Image(); button71.src = "images/button71.gif";
     button80 = new Image(); button80.src = "images/button80.gif";
     button81 = new Image(); button81.src = "images/button81.gif";
     button90 = new Image(); button90.src = "images/button90.gif";
     button91 = new Image(); button91.src = "images/button91.gif";
     versum0 = new Image(); versum0.src = "images/versum0.gif";
     versum1 = new Image(); versum1.src = "images/versum1.gif";
}
  
function change(Image,No) {
     if (!document.images) {}
     else document[Image].src = eval(Image + No + ".src");
}