BAPI_PO_CREATE1 FAILURE exception raised

Hello all,

I'm using FM BAPI_PO_CREATE1 to create purchase orders. The function works fine for one order.

In a loop I have to create more than one orders and when the FM(BAPI_PO_CREATE1) is call for the second order is raised RAISE_EXCEPTION (Exception condition "FAILURE" raised.)

Can you tell which is the cause of this exception or how to fix this problem? Should I call BAPI_TRANSCATION_COMMIT after all the FM calls?

Thank you!

Bogdan