if(document.images) {
  arr_on = new Image();
  arr_on.src = "/images/arr2_.gif";
  arr_off = new Image();
  arr_off.src ="/images/arr2.gif";
  arr2_on = new Image();
  arr2_on.src = "/images/arr2_.gif";
  arr2_off = new Image();
  arr2_off.src ="/images/arr2.gif";
  dsnby_on = new Image();
  dsnby_on.src = "/images/bot2_.gif";
  dsnby_off = new Image();
  dsnby_off.src ="/images/bot2.gif";
 }

function img_on(iName) {
 if(document.images) {
  imgOn = eval(iName + "_on.src");
  document [iName].src = imgOn;
  return true;
 }
}

function img_off(iName) {
 if(document.images) {
  imgOff = eval(iName + "_off.src");
  document [iName].src = imgOff;
  return true;
 }
}