var TimeToFade = 1000.0;

/*main function*/
function frontPageDiv() {
    var screenWidth = document.documentElement.clientWidth;
    var popupWidth = 952;
    var leftOffset = (screenWidth - popupWidth) / 2;
    document.getElementById("popupDiv").style.left = leftOffset + "px";
    setTimeout('closePopup()', 10000)
}

function closePopup() {
    fade('popupDiv');
    fade('faderDiv');
    //document.getElementById("popupDiv").style.display = "none";
    //document.getElementById("faderDiv").style.display = "none"; 
}

function fade(eid) {
    var element = document.getElementById(eid);
    if (element == null)
        return;

    if (element.FadeState == null) {
        if (element.style.opacity == null
        || element.style.opacity == ''
        || element.style.opacity == '1') {
            element.FadeState = 2;
        }
        else {
            element.FadeState = 2;
        }
    }

    if (element.FadeState == 1 || element.FadeState == -1) {
        element.FadeState = element.FadeState == 1 ? -1 : 1;
        element.FadeTimeLeft = TimeToFade - element.FadeTimeLeft;
        
    }
    else {
        element.FadeState = element.FadeState == 2 ? -1 : 1;
        element.FadeTimeLeft = TimeToFade;
        setTimeout("animateFade(" + new Date().getTime() + ",'" + eid + "')", 33);
    }
}

function animateFade(lastTick, eid) {
    var curTick = new Date().getTime();
    var elapsedTicks = curTick - lastTick;

    var element = document.getElementById(eid);

    if (element.FadeTimeLeft <= elapsedTicks) {
        element.style.opacity = element.FadeState == 1 ? '1' : '0';
        element.style.filter = 'alpha(opacity = '
        + (element.FadeState == 1 ? '100' : '0') + ')';
        element.FadeState = element.FadeState == 1 ? 2 : -2;
        document.getElementById(eid).style.display = "none";
        return;
    }

    element.FadeTimeLeft -= elapsedTicks;
    var newOpVal = element.FadeTimeLeft / TimeToFade;
    if (element.FadeState == 1)
        newOpVal = 1 - newOpVal;

    element.style.opacity = newOpVal;
    element.style.filter = 'alpha(opacity = ' + (newOpVal * 100) + ')';

    setTimeout("animateFade(" + curTick + ",'" + eid + "')", 33);
}