Screen exit SRVEUSCR field values in ML81N service entry sheet

Hi,

I want to add custom fields in service entry sheet table ESSR, for this I have use enhancement SRVEUSCR, first I have added the additional fields in the include CI_ESSRDB, then in Custom subscreen 'SAPLXMLU 0399' I have added the required field from ESSR on the screen.

Now the added fields are coming properly in the ML81N screen as Additional Data, Now the values in additional fields are depend on the values of ESSR-EBELN and ESSR-EBELN field but in function exit

               EXIT_SAPLMLSR_020

               EXIT_SAPLMLSR_021,

I can see only the include fields CI_ESSRDB, other field of ESSR are not coming on which I want to set the values of my custom fields.

  So in which exit I can add the code, to get the the values in my custom field depending on ESSR-EBELN and ESSR-EBELP.

Regards,

Zafar