The code should look something like this -
DEFINE VARIABLE m_flag AS LOGICAL NO-UNDO.
{gprunp.i "gpglvpl" "p" "initialize"}
{gprunp.i "gpglvpl" "p" "set_disp_msgs" "(input false)"}
{gprunp.i "gpglvpl" "p" "validate_fullcode"
"(INPUT poacct, input posub,
input pocc, """",
OUTPUT m_flag)"}...