if (document.images)
   {
     imgover= new Image();
     imgover.src="http://www.gotcancer.org/menu_mouseover.gif";  

     imgout= new Image();
     imgout.src="http://www.gotcancer.org/menu_mouseout.gif";

     imgdown= new Image();
     imgdown.src="http://www.gotcancer.org/menu_mousedown.gif";
   }


function initMenu(strName)
{
  document[strName].src!=imgdown.src;
}


function setImg(imgName, strMouseEvent)
 {
   if (document.images)
    {
     document[imgName].src= eval("img" + strMouseEvent + ".src");
    }
 }