var version4 = (navigator.appVersion.charAt(0) == "4");
var popupHandle;

function closePopup() {
    if (popupHandle != null && !popupHandle.closed) popupHandle.close();
}

function displayPopup(url, name, height, width) {
    var properties = "resizable=yes, scrollbars=yes, toolbar = 0, location = 0, height = " + height;
    properties = properties + ", width=" + width;
    var leftprop, topprop, screenX, screenY, cursorX, cursorY, padAmt;
    if (navigator.appName == "Microsoft Internet Explorer") {
        screenY = document.body.offsetHeight;
        screenX = window.screen.availWidth;
    }
    else {
        screenY = window.outerHeight
        screenX = window.outerWidth
    }

    screenX = screen.Width;
    screenY = screen.Height;


    leftvar = (screenX - width) / 2;
    rightvar = (screenY - height) / 2;
    if (navigator.appName == "Microsoft Internet Explorer") {
        leftprop = leftvar;
        topprop = rightvar;
    }
    else {
        leftprop = (leftvar - pageXOffset);
        topprop = (rightvar - pageYOffset);
    }

    properties = properties + ", left = " + leftprop;
    properties = properties + ", top = " + topprop;

    closePopup();
    popupHandle = open(url, name, properties);
}
//  End -->