(function($) {
	$.fn.extend({
		center : function(options) {
			var options = $.extend({ // Default values
				inside : window, // element, center into window
				transition : 0, // millisecond, transition time
				minX : 0, // pixel, minimum left element value
				minY : 0, // pixel, minimum top element value
				vertical : true, // booleen, center vertical
				withScrolling : true, // booleen, take care of element inside
										// scrollTop when minX < 0 and window is
										// small or when window is big
				horizontal : true
			// booleen, center horizontal
			}, options);
			return this.each(function() {
				var props = {
					position : 'absolute'
				};
				if (options.vertical) {
					var top = ($(options.inside).height() - $(this).outerHeight()) / 2;
					if (options.withScrolling)
						top += $(options.inside).scrollTop() || 0;
					top = (top > options.minY ? top : options.minY);
					$.extend(props, {
						top : top + 'px'
					});
				}
				if (options.horizontal) {
					var left = ($(options.inside).width() - $(this).outerWidth()) / 2;
					if (options.withScrolling)
						left += $(options.inside).scrollLeft() || 0;
					left = (left > options.minX ? left : options.minX);
					$.extend(props, {
						left : left + 'px'
					});
				}
				if (options.transition > 0)
					$(this).animate(props, options.transition);
				else
					$(this).css(props);
				return $(this);
			});
		}
	});
})(jQuery);