var myimages=new Array()
myimages[1]="images/header.jpg";
myimages[2]="images/header2.jpg";
myimages[3]="images/header3.jpg";
var rand=Math.floor(Math.random()*myimages.length);
if (rand==0) rand=1;
var header = document.getElementById("noflash");
header.style.background = 'url("'+myimages[rand]+'")';