var a=new Array(7);
var win=null;

function preloadmyimg() {
for (i = 1; i <= 6; i++) {
if (document.images) {
a[i] = new Image();
a[i].src = "images/button_"+i+".gif";
}}}

function mymenu(x) {
myname = "button"+x;
document.all[myname].src = "images/button_"+x+"a.gif";
}

function mymenuo(x) {
myname="button"+x;
document.all[myname].src = "images/button_"+x+".gif";
}