I have a situation where I will be adding/updating one type of record from an ascx.  In addition, the record being manipulated can have a dependent set of record(s).  There is a second ascx which will list these dependent records (if any) and allow addition of new records or modification of existing ones.

My quandry is:  if the primary record is new, I do not want to allow entry of any dependent records until I have created the primary record and retrieved its key.  The easiest way I can think of to do this is to make the add button inactive until I have a primary key.  My problem is that I don't know how to do this.

First ascx is named AddUpdateClientControl.ascx; second ascx is AddUpdatePhoneControl.ascx.  Each ascx will have its own btnAdd control.  In the first ascx file, I'd like to activate the btnAdd in the second ascx.

All help will be appreciated.