jQuery.fn.center = function (absolute) {
    return this.each(function () {
        var t = jQuery(this);

        t.css({
            position:    absolute ? 'absolute' : 'fixed', 
            left:        '50%', 
            zIndex:        '99'
        }).css({
            marginLeft:    '-' + (t.outerWidth() / 2) + 'px', 
        });

        if (absolute) {
            t.css({
                marginLeft:    parseInt(t.css('marginLeft'), 10) + jQuery(window).scrollLeft()
            });
        }
    });
};