if (document.images) {
  image1on = new Image();
  image1on.src = "img/m1_2.gif";
  image1off = new Image();
  image1off.src = "img/m1_1.gif";

  image2on = new Image();
  image2on.src = "img/m2_2.gif";
  image2off = new Image();
  image2off.src = "img/m2_1.gif";

  image3on = new Image();
  image3on.src = "img/m3_2.gif";
  image3off = new Image();
  image3off.src = "img/m3_1.gif";

  image4on = new Image();
  image4on.src = "img/m4_2.gif";
  image4off = new Image();
  image4off.src = "img/m4_1.gif";

  image5on = new Image();
  image5on.src = "img/m5_2.gif";
  image5off = new Image();
  image5off.src = "img/m5_1.gif";

  image6on = new Image();
  image6on.src = "img/m6_2.gif";
  image6off = new Image();
  image6off.src = "img/m6_1.gif";

  image7on = new Image();
  image7on.src = "img/m7_2.gif";
  image7off = new Image();
  image7off.src = "img/m7_1.gif";

  image8on = new Image();
  image8on.src = "img/m8_2.gif";
  image8off = new Image();
  image8off.src = "img/m8_1.gif";

  image9on = new Image();
  image9on.src = "img/m9_2.gif";
  image9off = new Image();
  image9off.src = "img/m9_1.gif";


    }function turnOn(imageName) {
  if (document.images) {
    document[imageName].src = eval(imageName + "on.src");
  }
}
function turnOff(imageName) {
  if (document.images) {
    document[imageName].src = eval(imageName + "off.src");
  }
}