$.fn.centerInClient = function (options) {
    /// <summary>Centers the selected items in the browser window. Takes into account scroll position.
    /// Ideally the selected set should only match a single element.
    /// </summary>    
    /// <param name="fn" type="Function">Optional function called when centering is complete. Passed DOM element as parameter</param>    
    /// <param name="forceAbsolute" type="Boolean">if true forces the element to be removed from the document flow 
    ///  and attached to the body element to ensure proper absolute positioning. 
    /// Be aware that this may cause ID hierachy for CSS styles to be affected.
    /// </param>
    /// <returns type="jQuery" />
    var opt = { forceAbsolute: false,
        container: window,    // selector of element to center in
        completeHandler: null
    };
    $.extend(opt, options);

    return this.each(function (i) {
        var el = $(this);
        var jWin = $(opt.container);
        var isWin = opt.container == window;

        // force to the top of document to ENSURE that 
        // document absolute positioning is available
        if (opt.forceAbsolute) {
            if (isWin)
                el.remove().appendTo("body");
            else
                el.remove().appendTo(jWin.get(0));
        }

        // have to make absolute
        el.css("position", "absolute");

        // height is off a bit so fudge it
        var heightFudge = isWin ? 2.0 : 1.8;

        var x = (isWin ? jWin.width() : jWin.outerWidth()) / 2 - el.outerWidth() / 2;
        var y = (isWin ? jWin.height() : jWin.outerHeight()) / heightFudge - el.outerHeight() / 2;

        el.css("left", x + jWin.scrollLeft());
        el.css("top", y + jWin.scrollTop());

        // if specified make callback and pass element
        if (opt.completeHandler)
            opt.completeHandler(this);
    });
}