Custom Controls using Collections

Question

Hi there Background: I am busy writing a custom control in C#, the control must have two comboboxes on it and a button. When the user selects a item in the first combobox the values in the second one must change, like master-detail, the button mustn't do anything atm. The items in these comboboxes are dynamically add through the page by means of objects and collections. This control is used on my pages if an error is caught, then the page should implement this control to give the user options on what to do next. Problem: I am stuggling with the two comboboxes, if I select a item in the first one and do a postback, the values are lost. I did databind them and that didn't solve the problem. I would like to know if someone can help me with this. Thanks anyway WynandJJ