function lightup(imgName)
	 {
	   if (document.images)
	    {
	      imgOn=eval(imgName + "_on.src");
	      document[imgName].src= imgOn;
	    }
	 }

	function pushin(imgName)
	 {
	   if (document.images)
	    {
	      imgOn=eval(imgName + "_push.src");
	      document[imgName].src= imgOn;
	    }
	 }

	function turnoff(imgName)
	 {
	   if (document.images)
	    {
	      imgOff=eval(imgName + "_off.src");
	      document[imgName].src= imgOff;
	    }
       }