function preload(pix) {
preld = new Array();
for (i = 0; i < pix.length; i++) {
preld[i] = new Image();
preld[i].src = pix[i];
}
}
function buttonLight(num, imgname) {
imgname.src = preld[num].src;
}
button = new Array();
button[0]  = "images/but1a.gif";
button[1]  = "images/but1b.gif";
button[2]  = "images/but2a.gif";
button[3]  = "images/but2b.gif";
button[4]  = "images/but3a.gif";
button[5]  = "images/but3b.gif";
button[6]  = "images/but1a.gif";
button[7]  = "images/but1b.gif";
button[8]  = "images/but2a.gif";
button[9]  = "images/but2b.gif";
button[10]  = "images/but3a.gif";
button[11]  = "images/but3b.gif";
preload(button);