Save custom fields value in EKKO through ME21N

Question

Hello Friends,
putting a new inputfield in the header of ME21N - PO transaction must be inserted within existing tabstrib "Additional Data".
This the new requirement.
I have used the enhancement "MM06E005". I have only implemented and activated the USEREXIT without writing
any code in any Function Module.
Additionally I have added through the screen painter (Function Pool MEGUI) into screen 1229 the customer
ZFIELD (Textinputfield).
I can see this field in the transaction ME21N, ME22N, ME23N but if I enter any value and save it. This Field has only 0000000 in the EKKO instaed of the entered value by me.
In the other transaction like ME21 ME22 ME23 this problem is not existing. I can save the enterd date without any problem.
I have already implemented the structure CI_EKKODB too. There is the zcustom field added.
I need your  help for in how to save the data in EKKO with me21n.
Kindly Regards
Marco

Answer 1

Dear Marco,
Dont use User Exit for this . Use the BADI's .If uses the USer Exit it will create u some probs at later stage.
There are 2 BADI's available for this.
1) ME_PROCESS_PO_CUST.
2) ME_GUI_PO_CUST.
1) ME_PROCESS_PO_CUST.This BADI is for Validating the PO at various Level. Methods for this BADI is
1.Open.
2.Initialize.
3.Process Header.
4.Process Item.
5.Check.
6.Post.
Etc.
So u can Validate the Entire PO ..
2. ME_GUI_PO_CUST.
Adding the Customer Own Screen to Enjoy Purchase Order.
The Process is that Just Create a Function Group with the Screen with Screen Which u want to Add to the Header Level.
Through this BADI u can add N Number of Screen to PO.
In the First Method of this BADI just Add the Screen. For Better Understanding goto the Sample Coding of Both BADI's.
With Regards,
Sumodh.P