Default values on QT when main table record is added ??

Hi All,

I need to put in some default values on the Qualified table when a new record is added on the main table.I tried to run Assigned from main table on the corresponding qualified field to QT.But it was unsuccessful and said "Assignment failed".Is there any way to go through this scenario?I l already had some input from sdn members suggesting that i cannot run assignments from main table to QT.

Any Suggestions...