(function($) {
	$.fn.vCenter = function(refHeight) {
		return this.each(function(i) {
			$(window).load(function() {
				var ah = $(this).height();
				if (typeof(refHeight) === 'undefined') refHeight = $(this).parent().height();
				var mh = Math.ceil((refHeight - ah) / 2);
				$(this).css('margin-top', mh);
			});
		});
	};
})(jQuery);