Control not found

Hi,

I have a page that uses AJAX tabs and containers. A DropDownList control (DrpProject) has a sqlDataSource that has a selectparameter:

    <SelectParameters>

     <asp:ControlParameterControlID="DrpProject"DefaultValue="0"Name="ProjectID"PropertyName="SelectedValue"/> 

   </SelectParameters>

I get the following runtime  error message:

Could not find control 'DrpProject' in ControlParameter 'ProjectID'. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: Could not find control 'DrpProject' in ControlParameter 'ProjectID'.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. 

Thank you.