/**
 *
 * jQuery Random plugin
 *
 * @author   Michel Belleville <michel.belleville@gmail.com>
 * @version  1.1.0
 * @requires jQuery v1.3.2 or later
 * @license  GPLv3 [http://www.gnu.org/licenses/gpl.html]
 * 
 * @description Picks element(s) at random in a selection.
 * @param integer num (optional) number of elements to pick
 * 
 * Use :
 * $('#whatever .you .like').random();
 * $('.you_can_event select .more_than_one').random(10);
 * 
 */
(function($) {
	jQuery.fn.random = function(num) {
		num = parseInt(num);
		if (num > this.length) 
			return this.pushStack(this);

		if (! num || num < 1) 
			num = 1;

		var to_take = new Array();
		this.each(function(i) { 
			to_take.push(i); 
		});

		var to_keep = new Array();
		var invert = num > (this.length / 2);
		if (invert) num = this.length - num;

		for (; num > 0; num--) {
			for (var i = parseInt(Math.random() * to_take.length); i > 0; i--)
			    to_take.push(to_take.shift());

			to_keep.push(to_take.shift());
		}

	    if (invert) to_keep = to_take;

		return this.filter(function(i) { return $.inArray(i, to_keep) != -1; });
  };
}) (jQuery);