Track Google Analytics and Google AdWords conversions on click with jQuery

/*!
* Conversion Tracker: a jQuery Plugin that tracks an event in both Google Analytics and Google AdWords
* @author: Tim Gaunt (@timgaunt)
* @url: http://blogs.thesitedoctor.co.uk/tim
* @documentation: http://blogs.thesitedoctor.co.uk/tim
* @published: 24/10/2012
* @license Creative Commons Attribution Non-Commercial Share Alike 3.0 Licence
*		   http://creativecommons.org/licenses/by-nc-sa/3.0/
*
* ----------------------
* Usage
* ----------------------
* $('a').trackConversion({ goalId: Your AdWords Id });
*
*/
;if(typeof jQuery != 'undefined') {
	jQuery(function($) {
		$.fn.extend({
			trackConversion: function(options) {
				var settings = $.extend({}, $.fn.trackConversion.defaults, options);
			
				return this.each(function () {
					var $$	= $(this),
						o	= $.metadata ? $.extend({}, settings, $$.metadata()) : settings;

					$$.click(function(e){
						if(getValue($$, o.trackAnalytics) && (typeof _gaq != 'undefined')){
							_gaq.push(['_trackEvent', getValue($$, o.label), getValue($$, o.action), getValue($$, o.value)]);
						}
						
						if(getValue($$, o.trackAdWords) && getValue($$, o.goalId) > 0){
							var randomNum = new Date().getMilliseconds();
							var trackUrl = "http://www.googleadservices.com/pagead/conversion/" + getValue($$, o.goalId) + "/?random=" + randomNum + "&value=" + getValue($$, o.conversionValue) + "&label=" + getValue($$, o.label) + "&guid=ON&script=0&url=" + getValue($$, o.url);
							$('<img />', {src:trackUrl, width:1, height:1 }); 
						}
					});
				});

				function getValue(link, value) {
					return (typeof value !== "function") ? value : value(link);
				}
			}
		});

		$.fn.trackConversion.defaults = {
			trackAnalytics:true,
			trackAdWords:true,
			url: function(){ return encodeURI(location.href); },
			goalId: 0,
			label: "Conversion",
			action: "Click",
			value: "",
			conversionValue: 1
		};

	}(jQuery));
}