In Google's documentation it is said that an event can be tracked in the following way:
<a onclick="_gaq.push(['_trackEvent', 'category', 'action', 'opt_label', opt_value]);">click me</a>
or older version:
<a onclick="pageTracker._trackEvent('category', 'action', 'opt_label', opt_value);">click me</a>
I was looking with Firebug to the request that are made when a click on a link and I see there aborted request:
http://www.google-analytics.com/__utm.gif?utmwv=4.7.2&utmn=907737223&....
This happens because browser unload all javascript when user navigates to a new page. How in this case event tracking is performed?
Edit:
Since one picture can be worth a thousand words...
When I click a link firebug shows me this sequence of requests (here are shown first four, after follows requests to fill page content)