10 ' test VARPTR and VARPTR$ on undefined variables 
20 OPEN "OUTPUT.TXT" FOR OUTPUT AS 1
30 ON ERROR GOTO 1000
100 PRINT#1, VARPTR(A)
110 PRINT#1, VARPTR(B(9))
120 PRINT#1, VARPTR(C(12))
200 PRINT#1, VARPTR$(D)
210 PRINT#1, VARPTR$(E(9))
220 PRINT#1, VARPTR$(F(12))
300 CLOSE
999 END
1000 PRINT#1, "error:" err " in " erl
1010 RESUME NEXT

