Creation of Service POs using BAPI_PO_CREATE1

Hi Friends,

I am trying to create service POs through BAPI (BAPI_PO_CREATE1). I am facing different errors like Please maintain service or limits eve though I am providing the details in POSERVICES. Can any one suggest me the fields which we have to provide for creating the service POs.

I am using this BAPI in LSMW.

Thanks,

Gagan Chodhry