I've a client who is still running on SAP 4.6C. There is a requirement to validate the Account Assignment Field KNTTP based on the document type, and if the validation fails, to raise an error message. As there is no standard user exit that I've been able to find for this field, and we don't want to modify standard screens, I've created a field exit against the KNTTP field and generated the FM FIELD_EXIT_KNTTP, and activated it, but it doesn't work.
As this is the first Field Exit I've coded could someone please assist me with understanding the following: in the parameters list is the value of INPUT the value of, in this instance, the KNTTP field and also is it possible to read other screen data within this FM, for example, if the KNTTP value eq 9, can I read the BSART field of the current transaction, and if so, how do I reference it (BSART, EKKO-BSART, MEREQ_TOPLINE-BSART, parameter id BSA, etc)?
Any suggestions on how to debug the process would be greatly appreciated as well.
Any help would be greatly appreciated.