var bgImg = new Array()

bgImg[0] = 'background-master.jpg'
bgImg[1] = 'background-master2.jpg'
var j = 0
var p = bgImg.length;
var preBuffer = new Array()
for (i = 0; i < p; i++) {
    preBuffer[i] = new Image()
    preBuffer[i].src = bgImg[i]
}
var whichImage = Math.round(Math.random()*(p-1));
function chooseBg() {
    document.write('<style type="text/css"> body, html { background-image:url(/Style%20Library/Images/Greenwood/' + bgImg[whichImage] + ');</style>');
}