Debugging Idoc Acc_document02

Hi Gurus ,

I want to debug the idoc Acc_document02 and message type is Acc_document in Inbound function module in we19 .

In the dialogue box i click the function module search help i get two Bapi , Bapi_idoc_input1 and Bapi_idoc_inputp. which one should i select and whats the difference between these two Bapi.

Thanks,

Lakshmi Rajkumar.