/*
MenuButtonOff1 = new Image();
MenuButtonOff1.src = "images/menu_button-off_1.png";
MenuButtonOn1 = new Image();
MenuButtonOn1.src = "images/menu_button-on_1.png";

MenuButtonOff2 = new Image();
MenuButtonOff2.src = "images/menu_button-off_2.png";
MenuButtonOn2 = new Image();
MenuButtonOn2.src = "images/menu_button-on_2.png";

MenuButtonOff3 = new Image();
MenuButtonOff3.src = "images/menu_button-off_2.png";
MenuButtonOn3 = new Image();
MenuButtonOn3.src = "images/menu_button-on_2.png";
*/

function changeImage(imageNo, image1, image2) {
  ImageBefore = new Image();
  ImageBefore.src = image1;
  ImageAfter = new Image();
  ImageAfter.src = image2;

  window.document.images[imageNo].src = ImageAfter.src;
}