INCLUDE "D2:CHARTEST.ACT" ;from the Action! Tool Kit

BYTE FUNC Verify(CHAR ARRAY code)
  BYTE i,c,v
  CARD sum

  IF code(0)#9 THEN
    RETURN (0)
  ELSEIF IsDigit(code(1))=0 THEN
    RETURN (0)
  FI

  sum=0
  FOR i=2 TO code(0)
  DO
    c=code(i)
    IF IsDigit(c) THEN
      v=c-'0
    ELSEIF IsAlpha(c) THEN
      v=ToUpper(c)-'A+10
    ELSEIF c='* THEN
      v=36
    ELSEIF c='@ THEN
      v=37
    ELSEIF c='# THEN
      v=38
    ELSE
      RETURN (0)
    FI

    IF (i&1)=0 THEN
      v==*2
    FI

    sum==+v/10+v MOD 10
  OD

  v=(10-(sum MOD 10)) MOD 10
  IF v#code(1)-'0 THEN
    RETURN (0)
  FI
RETURN (1)

PROC Test(CHAR ARRAY code)
  Print(code)
  IF Verify(code) THEN
    PrintE(" is valid")
  ELSE
    PrintE(" is invalid")
  FI
RETURN

PROC Main()
  Put(125) PutE() ;clear the screen
  Test("037833100")
  Test("17275R102")
  Test("38259P508")
  Test("594918104")
  Test("68389X106")
  Test("68389X105")
RETURN