I am referring specifically to the jQuery Autocomplete v1.1 plugin by Jörn Zaefferer [source: http://bassistance.de/jquery-plugins/jquery-plugin-autocomplete/] as there seems to
But you can first check/debug for value of $(this).attr('name').
Also one more thing as here explained [in options tab], you can check with Firebug to see ajax post request(for url and it's data) which will help you to resolve the problem.