STATUS 51 ERROR in ale idoc

HI ALL

i have created idoc sending data from client 500 to 510 updating table PA0105. When record not exits in 510 it is creating new record. If record is exits in the 510 idoc is giving error as status 51 as "Infotype 0105 cannot be updated on database tabl

table pa0105".

i have to update record if record is exits.

Please help me out.

Thanks in Advance.

Regards

sai