// function to open new window
function openDemo(url){
    w = 660;
    h = 525;
    leftVal = (screen.width / 2)-((w/2)+10);
    topVal = (screen.height / 2)-((h/2)+50);

    params = 'width='+w+', height='+h+', resizable=no, scrollbars=no, toolbars=no, location=no, directories=no, status=no, menubar=no, copyhistory=no, left='+leftVal+',top='+topVal;
    var fwin = window.open(url, 'demoWin', params);
    if (fwin && window.focus) fwin.focus();
}

var photos = new Array();

photos[0] = "letterbox1.jpg";
photos[1] = "letterbox2.jpg";
photos[2] = "letterbox4.jpg";
photos[3] = "letterbox5.jpg";
photos[4] = "letterbox6.jpg";
photos[5] = "letterbox8.jpg";
photos[6] = "letterbox9.jpg";

var whichSet = Math.round(Math.random()*(photos.length-1));