c# pass selected value from dropdownlist to accessdatasource selectparameter
<p>I have an access data source which loads a listbox values. I am trying to pass a parameter to the accessdatasource but I'm not sure what I am doing wrong. </p>

<pre><code>&lt;asp:DropDownList ID="customerName" runat="server"&gt;
    &lt;asp:ListItem value="69" Text="Danny"&gt;&lt;/asp:ListItem&gt;
    &lt;asp:ListItem value="23" Text="Sarah"&gt;&lt;/asp:ListItem&gt;
&lt;/asp:DropDownList&gt;

&lt;asp:AccessDataSource ID="AccessDataSource1" runat="server" DataFile="/App_Data/data.mdb" SelectCommand="SELECT * FROM table WHERE customerID='?'"&gt;

&lt;selectparameters&gt;
    &lt;asp:ControlParameter Name="customerID" ControlID="customerName" PropertyName="SelectedValue" /&gt;
&lt;/selectparameters&gt;

&lt;asp:ListBox ID="lstCustomers" runat="server" AutoPostBack="True" 
        DataSourceID="AccessDataSource1" DataTextField="customerName" 
        DataValueField="customerID" Width="175px" Height="365px" 
            onselectedindexchanged="lstCustomers_SelectedIndexChanged"&gt;&lt;/asp:ListBox&gt;
</code></pre>

<p>The list comes back as blank... not sure what I'm doing wrong!</p>
