Dynamic dropdown based on user selection of another dropdown on the same page

Question

hi all, ok, I have a table which contains use data, a name,
and a userID. for the example lets say "Simon Bullen" and my userID
is "999".
on a form I have, there is a dropdown box, which is dynamic
from this table, and allows me to select Simon Bullen, however, I
have a hidden field on the form, which when the user selects "simon
bullen" the hidden field populates with the appropiate U number
from the same table.... no i thought this would do it:
<cfquery name="userNumber" datasource="userList">
SELECT userNumber FROM dbo.Users WHERE Name =
<cfqueryparam value="#form.Name#">
</cfquery>
and then my dynamic form field (hidden) would reference to
this query....
but it doens't work, could somebody please enlighten me? I'm
hoping its something silly
Thanks in advance

Answer 1

You could make the value of the option the UserID and the
option display the name.
If that isn't what you need, I think you'll need some
javascript to populate your hidden field based on what is chosen in
the select.
I think you can modify this:
http://www.javascriptkit.com/javatutors/selectcontent2.shtml
...to populate your hidden field instead of a new select
list.
If there's a way to do that without JS I'm not aware of it.
A third possibility: look up the UserID (based on the name
chosen) after the form is submitted then do with it whatever you
need to.