AutoComplete

Hi guys, can  anyone tell me if the AutoComplete widget supports showing one value but storing another?  You know, kindof like a select box has both a value that differs from the displayed text.

I know the 2.3 version did by using a hidden field to store the actual value saved in the form but it looks like the widget has changed in 2.4.  I'm having a hard time following the JS code that supports the AutoComplete widget.  It's like it's magic!

Here is a sample that I pulled from Cubi, how can I modify to get this desired affect?

  <Element Name="qry_
username" Class="AutoSuggest" FuzzySearch="Y"

SelectFrom="system.do.UserDO[
username],[username] like '%{$_POST['client_id']}%' GROUP BY [username]"
FieldName="qry_username" cssFocusClass="input_text_search_focus"

CssClass="input_text_search" />