Function module for updating a custom idoc

hi all,

i had a requirement in which i had to send a custom idoc from one application server to another. i did it but now i task is the generated idoc from sender should be updaetd to database tables of receiver . for this we have to code some thing in receiver function modules . how to do it. in this issue i 'm having some doubts

1. the Fm at receiver side should be a updated FM or Remote-enabled FM

2. how to code this FM so that the data in idoc which is send from sender to reciver should be updated to databse tables of receiver.

please help me............ its very urgent..........

Thanks in advance,

Suresh Aluri.