title: GridViewDataComboBoxColumn: Taking value into datasource, updating problem
body: <p>I'm working on a project using a Gridview and inside are 3 comboboxes (ComboboxColumn).</p>
  <p>My first request when the page loads shows the different years where an organisation has a project in this year.
  When the year is chosen, I want second combobox to update it's values depending on the year choice.
  I'm using</p>
  <pre><code>&lt;asp:SqlDataSource &gt;&quot;
              SelectCommand=&quot;SELECT distinct [Nom_orga] FROM [T_Organisme] o
              inner join TR_Projet_Organisme t on o.ide_orga=t.ide_orga
              inner join T_Projet p on t.ide_proj = p.ide_proj
                  where Ind_etrng = 0
  
                  and ([Ann_finan] = @Ann_finan)
                         ORDER BY [Nom_orga] 
                          &quot;&gt;
                          &lt;SelectParameters&gt;
                              &lt;asp:SessionParameter Name=&quot;Ann_finan&quot; SessionField=&quot;Ann_finan&quot; Type=&quot;String&quot; ***DefaultValue=&quot;2007-2008&quot;***/&gt;
                          &lt;/SelectParameters&gt;&lt;/asp:SqlDataSource&gt;
  </code></pre>
  <p>I have to pass a default value to the sqldatasource parameter, otherwise the 2d combobox doesn't show anything.</p>
  <p>Can someone please explain how to remove the default value so the 2d combobox shows the value depending on the 1th combobox automatically (without refreshing the page or sub-page?</p>
  <p>I tried numerous ways to go around, like with cookies, but the updating part after choosing a year value doesn't work because this is NOT a combobox. It's a GridViewDataComboBoxColumn PropertiesComboBox.</p>