; Check for existence of any appointment for a patient
;
; This API is an extrinsic function that returns 1 of 3 values.
; The API checks for the existence of appointment records.
;
; INPUT SDDFN : Patient's DFN number (required)
;
; OUTPUT 1 : Appointment(s) on file
; 0 : No appointment(s) on file
; -1 : Error
;
; ERROR CODES - 101 : Database is Unavailable
; 102 : Patient ID is required
; 110 : Patient ID must be numeric
; 114 : Invalid Patient ID
; 117 : SDAPI Error
;
; ERROR LOCATION : ^TMP($J,"SDAMA204","PATAPPT","ERROR")
;
; Check for proper parameter and return -1 if bad DFN
;
; Initialize node for error reporting