if(document.images) {  //preload images
  ts0 = new Image();  
  ts0.src="images/ts0.jpg";
  ts1 = new Image(); 
  ts1.src="images/ts1.jpg";
  lm0 = new Image();  
  lm0.src="images/lm0.jpg";
  lm1 = new Image(); 
  lm1.src="images/lm1.jpg";
  h0 = new Image();  
  h0.src="images/h0.jpg";
  h1 = new Image(); 
  h1.src="images/h1.jpg";
  sg0 = new Image();  
  sg0.src="images/sg0.jpg";
  sg1 = new Image(); 
  sg1.src="images/sg1.jpg";
  ch0 = new Image();  
  ch0.src="images/ch0.jpg";
  ch1 = new Image(); 
  ch1.src="images/ch1.jpg";
  lin0 = new Image();  
  lin0.src="images/lin0.jpg";
  lin1 = new Image(); 
  lin1.src="images/lin1.jpg";
  ws0 = new Image();  
  ws0.src="images/ws0.jpg";
  ws1 = new Image(); 
  ws1.src="images/ws1.jpg";

}


function swap(imageName, imageFile) {
   if(!document.images)
      return;
   eval('document.images[imageName].src = '+imageFile+'.src');
}