CJ20N - Transaction type

Hi everyone,

I have created few custom fields in CJ20N using SMOD: CNEX0007. My question is how can I find out the transaction type for this transaction - TRTYP = A / V so as to enable or disable the custom fields. I know this should be done in the PBO of screen exit. But, can you help me to identify the transaction type for the same.

Thanks in advance,

Hema