PROCESS
This process is always reached when all the final checks have beencompleted before a document is updated. However, at this stage, thedocument number has not yet been assigned.

INTERFACE
The current document headers (there will be more than one forcross-company code transactions, for example), the corresponding lineitems and the recurring entry data for the document header and theone-time account data are transferred to the additional component, forinformation purposes only. You must not edit this data. Instead, twoadditional tables (T_BKPFSUB and T_BSEGSUB) and the structure BKDF_SUBSTare also transferred. The contents of the fields that can be substitutedare entered in these tables. Field TABIX contains a line number whichshows from which line in T_BSEG or T_BKPF the field contents originate.
Note: There is no additional check after the substitution. You must notoverwrite an existing payment lock (for example, due to a workflowdefinition).

Example
In the second line of table T_BSEG, the field contents from SGTXT (itemtext) should be replaced by the entry 'TEST'. This basically requires astatement sequence in the form
READ TABLE T_BSEGSUB WITH KEY TABIX = 2.
T_BSEGSUB-SGTXT = 'TEST'.
MODIFY T_BSEGSUB INDEX SY-TABIX.
You must code this statement sequence in your own function module.