jQuery.fn.center = function(absolute) { return this.each(function() { var t = jQuery(this); t.css({ position: absolute ? 'absolute' : 'fixed', left: '50%', top: '50%', zIndex: '99' }).css({ marginLeft: '-' + (t.outerWidth() / 2) + 'px', marginTop: '-' + (t.outerHeight() / 2) + 'px' }); if (absolute) { t.css({ marginTop: parseInt(t.css('marginTop'), 10) + jQuery(window).scrollTop(), marginLeft: parseInt(t.css('marginLeft'), 10) + jQuery(window).scrollLeft() }) } }) };