Jquery Autocomplete Plugin onItemSelect not firing

Jquery Autocomplete Plugin onItemSelect not firing

I am using Jquery Autocomplete Plugin. In which I am fetching values from database and get loaded in list Whenever I select any Item It should do the postback is must for my requirement. I have written an javascript for it. which I have called on OnItemSelect but for what reasons this event is not firing at all.

I have added simple alert message to test but still it is not firing. What might be the cause can anyone help me out from these?
I would appreciate the help
Following is the autocomplete which i am using :
* Autocomplete - jQuery plugin 1.1pre
* * Copyright (c) 2007 Dylan Verheul, Dan G. Switzer, Anjesh Tuladhar, Jörn Zaefferer

Any help would be appreciated.

Regards

Asif,