QXtend Inbound Pre- and Postprocessors > Creating Custom Pre- and Postprocessing Programs
  
Creating Custom Pre- and Postprocessing Programs
The custom pre- and postprocessing programs must be written in the Progress 4GL. The program you create is called from a Progress program named mfww01b.p. This Progress program has procedures that your program can call to limit your programming task to the validations you require.