My page contains a Wizard Control with several steps. One of these steps has a dropdown list, "ddlCenter". A later step has a GridView. An Edit Template in that GridView contains another dropdown list that is populated based on the selected value of ddlCenter.

Every reference I make to ddlCenter in the "population function" gives the error, "Object reference not set to an instance of an object". I have tried direct - ddlCenter.SelectedValue, and indirect using FindControl.

This is driving me crazy. Am I missing something obvious? FYI, this is using VB.Net

Thank you in advance for your replies.