Hi shivaji,
First of all, you should not give the commitment item manually at the time entry. It should be auto derive..from FMDERIVE or GL master (as in your case).
And for the assignment of fund center in case of internal order, you can define a new derivation rule in FMDERIVE. In that you can define some DUMMY fund center for internal orders which will not consume any budget.
Regards,
Ankit K. Agarwal
