Observe_field

Hi Friends. Its me newb having one Problem. I have 3 dynamic dropdown menus.

select Company => select Department => Select Role.

I done this using Observe_field. Its all works fine in Firefox. But not in IE7 What would be the Problem. Pls Assist Me. Thanks ...

Here starts my code

<% remote_form_for( :userinfo, userinfo,:url => { :action => 'add' },                            :html => { :id => 'userCreateForm' } ) do |f| %>

<div class='Field'>    <label> Login :</label>    <div class='FieldInput'> <%= f.text_field :login %> </div>

    <div class='FieldError'>       <%= error_message_on( userinfo, :login ) -%>     </div> </div>

<div class='Field'>     <label>Company :</label>     <div class='FieldInput'>     <select id='userinfo[company_id]' name='userinfo[company_id]'>     <option id='company-option'>Select Company </option>     <%= options_from_collection_for_select( CompanyInfo.find( :all),"id","company_name" ) %>     </select>     <%= observe_field("userinfo[company_id]",         n => "changed",         :update => "userinfo[department_id]",         :url => {:action => :update_department},         :with => "'company_id='+value") %>

    </div>

   <div class='Field'>    <label> Department </label>    <div class='FieldInput'>    <select id='userinfo[department_id]' name='userinfo[department_id]'>       <option>Select Department </option>       <%= render( :partial => 'departments', :object => @departmentinfo,                    :locals => { userinfo => nil} ) if @departmentinfo %>    </select>

    <%= observe_field("userinfo[department_id]",         n => "changed",         :update => "userinfo[role_id]",         :url => {:action => :update_roles},         :with => "'department_id='+value") %>   </div>

  <div class='Field'>   <label> Role </label>     <div class='FieldInput'>     <select id='userinfo[role_id]' name='userinfo[role_id]'>       <option>Select Role </option>       <%= render( :partial => 'roles', :object => @rolesinfo,                                 :locals => { :userinfo => nil} ) if @rolesinfo %>    </select>   </div> <% end %>