Hi Archana,
use the table /AIF/STD_IDX_TBL to find the message log , you have to enable the AIF configuration under error handling to select the message from above mentioned table .
you can use the append structure to store the message value in table /AIF/STD_IDX_TBL and same will be used as selection screen values in /n/aif/err transaction.
Regards
Sukumar