Form post missing parameters for form elements

I'm having an issue where a form post does not contain the value of the
select box it contains. This problem happens after I update the the
select box using an observe_field triggered ajax call. The result of
the call is to call render :partial to re-generate just the select box
element. If I post before triggering the ajax request I get all the
correct parameters, afterwards, however I only get the commit, action
and controller parameters. I have already cleared the usual suspects,
forms improperly nested, etc.

If I have another element in the form but outside the partial that gets
re-rendered it's value is submitted with the form. Along this line I
figured I could have an on_change event on my select box so when
someone selects a value it could get assigned to a hidden text field
outside the partial. The javascript for all this works and I can
verify the hidden text field has the correct value (using the Firebug
javascript console) but when the form submits I get the original
unmodified value of that hidden text field.

This is what my form looks like (the relevant parts that is). Yes I
know these multiply nested tables for layout are hideous and it has
caused me no end of grief on this project, however, I did not write
them and I have absolutely no control over the html at this point
(short of rewriting it all myself). The first form's submit is not
relevant to this problem, just the org_id select box which triggers the
re-rendering of the partial inside the td with the userdata id. I have
tried making the target of the observe_field be a div, a span and a td
all with the same effect.

<td height="175" align="left" valign="top"><table width="552"
border="0" cellspacing="0" cellpadding="0" class="formcolumn">
<tr>
  <td width="87" height="25" align="left" valign="middle"
class="formLabelText">Organizations:</td>
  <td height="25"><table width="323" height="25" border="0"
cellpadding="0" cellspacing="0">
  <%= start_form_tag :action=>"edit" %>
  <tr>
    <td width="173"><span class="date">
  <%= select_tag "org_id", options_for_select(@orgs),
:class=>'broadcast' %>
  <%= observe_field( :org_id, :url=>{:action=>'change_org'},
:update=>'userdata') %>
    </span></td>
    <td width="150"><span class="formLabelText">
      <%= submit_tag "Edit", :class=>"inputsubmit" %>
    </span></td>
  </tr>
  <%= end_form_tag %>
</table></td>
</tr>
<tr>
  <td height="25" align="left" class="formLabelText">&nbsp;</td>
  <td height="25" align="left">&nbsp;</td>
</tr>
<tr>
  <td height="25" align="left" class="formLabelText">Select User:</td>
  <td height="25"><table width="323" height="25" border="0"
cellpadding="0" cellspacing="0">
  <%= start_form_tag :controller=>"user", :action=>"modify" %>
<tr>
  <td width="173"><span class="date" id="userdata">
    <%= render :partial=>"user_select" %>
  </span></td>
  <%= text_field_tag "hiddenuser", "-1", :type=>"hidden" %>
  <td width="150"><span class="formLabelText">
    <%= submit_tag "Edit", :class=>"inputsubmit" %>
  </span></td>
</tr>
<%= end_form_tag %>
</table></td>

Here is the partial:

<%= select_tag "user_id", options_for_select(@users),
:class=>'broadcast', :onchange=>"alert($('hiddenuser').text);
$('hiddenuser').text = $('user_id').value; alert($('hiddenuser').text)"
%>

Thanks in advance for any insights you can shed on this strange
problem.

David Koontz
Rising Tide Software

David Koontz wrote:

I'm having an issue where a form post does not contain the value of the
select box it contains. This problem happens after I update the the
select box using an observe_field triggered ajax call. The result of
the call is to call render :partial to re-generate just the select box
element. If I post before triggering the ajax request I get all the
correct parameters, afterwards, however I only get the commit, action
and controller parameters. I have already cleared the usual suspects,
forms improperly nested, etc.
...
  <td height="25"><table width="323" height="25" border="0"
cellpadding="0" cellspacing="0">
  <%= start_form_tag :action=>"edit" %>
  <tr>

     ...OMITTED...

  </tr>
  <%= end_form_tag %>
</table></td>

Try swapping the nesting of the form and the table.
In HTML you can have a form directly inside a <td>,
but not at a point at which a tbody or row tag is
expected.