How to add a serail no field in components screen in Subcontracting PO

Question

I need to Create Subcontract PO With BAPI_PO_CREATE1.Its working fine (With Batch).
My requirement is I need to map one more extra field as Serial No in the Component SCreen.
How can i add the Serail no field in the Subcontractiong with Components Screen and How to Update that with BAPI.
Anybody knows the solution,let me know.
Edited by: ksampath on Feb 8, 2011 3:12 PM

Answer 1

Thanks for early response Dan.
As per the document (It is available at  http://www.****************/Tutorials/ABAP/XD01/XD01.htm),
1) I created the screen group, I created the Badi implementations
2) Created the Implementation by giving a name and added code the method CHECK_ADD_ON_ACTIVE. and activated it
3) agian using  Business Add-in: Customer Subscreens  , i created one more implementation and in that added code to GET_TAXI_SCREEN  method. before this i created a screen with a field.and i created a function pool and activated everything.
4) after everthing i added the field in the kna1 table. when i execute the xd03 transaction code,  i can able to see my own tab ( which i was created) on the screen, and i am able to see the field with blank.
Now my questions are:
1) How to write the logic to get the field information from the kna1 when i enter the transaction xd03/.
2) how to save the field values to kna1 database table when i open it in change mode(xd02) and changed the value.
and where to write the logic?.
Please provide me the code snippet if you have any.
appriciate for your early response.
thanks again.
kp