if (document.images) {
button1on = new Image();
button1on.src = "images/but1on.gif";
button2on = new Image();
button2on.src = "images/but2on.gif";
button3on = new Image();
button3on.src = "images/but3on.gif";
button4on = new Image();
button4on.src = "images/but4on.gif";
button5on = new Image();
button5on.src = "images/but5on.gif";
button8on = new Image();
button8on.src = "images/but8on.gif";
button9on = new Image();
button9on.src = "images/but9on.gif";
button11on = new Image();
button11on.src = "images/but11on.gif";
buttoninon = new Image();
buttoninon.src = "images/interon.gif";
button12on = new Image();
button12on.src = "images/but12on.gif";
button1off = new Image();
button1off.src = "images/but1off.gif";
button2off = new Image();
button2off.src = "images/but2off.gif";
button3off = new Image();
button3off.src = "images/but3off.gif";
button4off = new Image();
button4off.src = "images/but4off.gif";
button5off = new Image();
button5off.src = "images/but5off.gif";
button8off = new Image();
button8off.src = "images/but8off.gif";
button9off = new Image();
button9off.src = "images/but9off.gif";
button11off = new Image();
button11off.src = "images/but11off.gif";
buttoninoff = new Image();
buttoninoff.src = "images/interoff.gif";
button12off = new Image();
button12off.src = "images/but12off.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");
}
}