help belongs_to_auto_completer model_auto_completer

hi,

im trying to integrate model_auto_completer. the dropdown is working
nicely, my userdefined function:
auto_complete_belongs_to_for_X_Y_Z works as well, but then im stuck.
via model_auto_completer_result i can see the id, either attached to the
model(eg account_ID) or via my own partial:
<ul>
     <% for author in @authors %>
     <li id="<%= author.id %>"><%=h author.title %></li>
     <% end %>
</ul>

but what i wann do is: as soon the user selected one entry out of the
dropdown, i need to populate the rest of the form with data related to
the unique ID of that record. so> how to i access the ID???

thx tom