/***
 * @title		Center
 * @version		2.0
 * @author		Andreas Lagerkvist
 * @date		2008-09-17
 * @url			http://andreaslagerkvist.com/jquery/center/
 * @license		http://creativecommons.org/licenses/by/3.0/
 * @copyright	2008 Andreas Lagerkvist (andreaslagerkvist.com)
 * @requires	jquery
 * @does		This little pluggy centers an element on the screen using either fixed or absolute positioning. Can be used to display messages, pop up images etc.
 * @howto		jQuery('#my-element').center(true); would center the element with ID 'my-element' using absolute position (leave empty for fixed).
 *
 * @exampleHTML
 * <p>I should be fixed centered</p>
 * <p>The paragraph above and the paragraph beneath this one are centered. They should be in the middle of the viewport.</p>
 * <p>I should be absolutely centered</p>
 *
 * @exampleJS
 * jQuery('#jquery-center-example p:first-child').center();
 * jQuery('#jquery-center-example p:last-child').center(true);
***/
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()
			});
		}
	});
};