// PRELOAD IMAGES FOR SWAPPING
if(document.images)
 {
   var square_open   = new Image(9,9);
   var square_closed = new Image(9,9);
  
   square_open.src   = path+"img/square_open2.gif";
   square_closed.src = path+"img/square_open3.gif";
 }

// FUNCTION TO SWAP TWO IMAGES
function swapImages(curImg,newImg)
 {
  if(document.images)
    {
      curImg.src=newImg.src;
    }
 }