POSTING_INTERFACE_DOCUMENT using tcode FBV1

hi everybody

im using the fm POSTING_INTERFACE_DOCUMENT to park a document using tcode FBV1

but its giving me error 'field BSEG_ZFBDT is not found on screen'

Basically I have just been appending the table FTPOST with the name of the screen fields and their values

I dont know how to handle to which screen they belong

can anybody help me