This demo shows how to set up a sequence of dependent drop-down controls. Select a year to refresh the make and model drop-downs, and select a make to refresh the model drop-down. Choosing a model loads the corresponding vehicle details.

The Code

In the Make drop-down's Change event, the following line of code reloads the Model drop-down:

page.findControl("Model").reload();

The Model control is populated with the following query:

select distinct Model
  from Vehicles
  where Year = @year
    and Make = @make
  order by Model