if (document.images) {
     r1c1a = new Image(73,19);
     r1c1a.src = "images/home.jpg";
     r1c1b = new Image(73,19);
     r1c1b.src = "images/home-w.jpg";
	  
     r1c2a = new Image(103,20);
     r1c2a.src = "images/contact.jpg";
     r1c2b = new Image(103,20);
     r1c2b.src = "images/contact-w.jpg";
     
          
    }

    function t_on(imgname) {
     if (document.images) {
      document.images[imgname].src = eval(imgname + "b.src");
          }
    }
    function t_off(imgname) {
     if (document.images) {
      document.images[imgname].src = eval(imgname + "a.src");
           }
    }