Maybe u can help with with some ajax issue.
I have AUTO COMPLETE code - I type the city name and the code auto-completes it for me and also get the city ID and supposed
Try using a div instead of a span tag for ajax_response_city. The html gets messed up and your selections won't work anymore.
I put together an example: http://jsfiddle.net/me2loveit2/86T4f/
<div id='ajax_response_city' class='ajax_response'></div>
I would also start using proper html (like put li elements in ul or ol) to avoid issues like that.