if (document.images) {

  o1on = new Image();
  o1on.src = "images/menu01o.gif";

  o2on = new Image();
  o2on.src = "images/menu02o.gif";

  o3on = new Image();
  o3on.src = "images/menu03o.gif";
  
  o4on = new Image();
  o4on.src = "images/menu04o.gif";
  
  o5on = new Image();
  o5on.src = "images/menu05o.gif";
  


  o1off = new Image();
  o1off.src = "images/menu01.gif";

  o2off = new Image();
  o2off.src = "images/menu02.gif";

  o3off = new Image();
  o3off.src = "images/menu03.gif";
  
  o4off = new Image();
  o4off.src = "images/menu04.gif";
  
  o5off = new Image();
  o5off.src = "images/menu05.gif";


}

function changeImages() {
  if (document.images) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = eval(changeImages.arguments[i+1] + ".src");
    }
  }
}