if (document.images) {
  but0ON = new Image();
    but0ON.src = "button0_on.jpg";
  but0OFF = new Image();
    but0OFF.src = "button0_off.jpg";

  but1ON = new Image();
    but1ON.src = "button1_on.jpg";
  but1OFF = new Image();
    but1OFF.src = "button1_off.jpg";

  but2ON = new Image();
    but2ON.src = "button2_on.jpg";
  but2OFF = new Image();
    but2OFF.src = "button2_off.jpg";

  but3ON = new Image();
    but3ON.src = "button3_on.jpg";
  but3OFF = new Image();
    but3OFF.src = "button3_off.jpg";

  but4ON = new Image();
    but4ON.src = "button4_on.jpg";
  but4OFF = new Image();
    but4OFF.src = "button4_off.jpg";

  but5ON = new Image();
    but5ON.src = "button5_on.jpg";
  but5OFF = new Image();
    but5OFF.src = "button5_off.jpg";

  but6ON = new Image();
    but6ON.src = "button6_on.jpg";
  but6OFF = new Image();
    but6OFF.src = "button6_off.jpg";

  but7ON = new Image();
    but7ON.src = "button7_on.jpg";
  but7OFF = new Image();
    but7OFF.src = "button7_off.jpg";
}
function buttonOn(imgName) {
   if (document.images) {
      document[imgName].src = eval(imgName + "ON.src");
   }
}
function buttonOff(imgName) {
   if (document.images) {
      document[imgName].src = eval(imgName + "OFF.src");
   }
}