if (document.images) {
	
	img1on = new Image();           // The onmouseover image
	img1on.src = "data/img/illu_enter_on_02.png";  
	img2on = new Image();
	img2on.src = "data/img/illu_enter_on_04.png";  
	img1off = new Image();          // The normally seen image
	img1off.src = "data/img/illu_enter_02.png"; 
	img2off = new Image();
	img2off.src = "data/img/illu_enter_04.png"; 
	
  }				  //This function changes the image when over.
    function imgOn(imgName) {
            if (document.images) {
            document[imgName].src = eval(imgName + "on.src");
            }
    }				   //This function changes the image back when off.
    function imgOff(imgName) {
            if (document.images) {
            document[imgName].src = eval(imgName + "off.src");        
            }
    }