var imageMax = 9;
var imageTimer = 90;  // secs

if (document.images) {
    for (var img=1;img<=imageMax;img++) {
        eval('var image' + img + ' = new Image();');
        eval('image' + img + '.src = "images/backgrounds/' + img + '.jpg";');
    }
}

function changeBackground(prevNo) {
    var e = $('#Page');

    imageNo = Math.floor(Math.random() * imageMax) + 1;
    while (imageNo == prevNo) {
        imageNo = Math.floor(Math.random() * imageMax) + 1;
    }
    if (prevNo == null) {
        e.css("background-image", "url(" + eval('image' + imageNo + '.src') + ")");
    } else {
        e.fadeOut(function() {
            e.css("background-image", "url(" + eval('image' + imageNo + '.src') + ")");
            e.fadeIn();
        });
    }

    var timer = setTimeout('changeBackground(' + imageNo + ')', imageTimer*1000);
}

$(document).ready(function() {
    changeBackground();
});