// load menu image files
 var imgOut = new Array(8);
 var imgOn  = new Array(8);

function load_default() {
 for (i=0; i < imgOut.length; i++) {
  var j = i + 1 - 0;
  imgOut[i] = new Image;
  imgOut[i] = "./img/menu" + [j] + ".jpg";
  imgOn[i]  = new Image;
  imgOn[i]  = "./img/menu" + [j] + "_on.jpg";
 }
}

function change_menu(imgNo, Flg) {
 var imgName = "menu" + imgNo;

 if (Flg == 'on') {
 document.images[imgName].src = imgOn[imgNo - 1];
 } else {
 document.images[imgName].src = imgOut[imgNo - 1];
 }
}