if (document.images) {
btn01on = new Image(150,253);btn01on.src = "images/btn01_ov.jpg";
btn02on = new Image(150,253);btn02on.src = "images/btn02_ov.jpg";
btn03on = new Image(150,253);btn03on.src = "images/btn03_ov.jpg";
btn04on = new Image(150,253);btn04on.src = "images/btn04_ov.jpg";
btn05on = new Image(150,253);btn05on.src = "images/btn05_ov.jpg";

btn01off = new Image(150,253);btn01off.src = "images/btn01.jpg";
btn02off = new Image(150,253);btn02off.src = "images/btn02.jpg";
btn03off = new Image(150,253);btn03off.src = "images/btn03.jpg";
btn04off = new Image(150,253);btn04off.src = "images/btn04.jpg";
btn05off = new Image(150,253);btn05off.src = "images/btn05.jpg";
}

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");
  }
}