When you have the client-side objects of the controls inside the Advanced Form, you could use their client-side APIs to enable/disable them. For more information about the client-side programming of these controls, you could refer to the following help articles: RadDatePicker Client Object
, RadTimePicker Client Object
, and RadComboBox Client Object
I hope this helps.
the Telerik team
If you want to get updates on new releases, tips and tricks and sneak peeks at our product labs directly from the developers working on the RadControls for ASP.NET AJAX, subscribe to their blog feed