"IF" & "THEN" treated as files

315 if ficecode in ('009137' '9137' '209137' '109137'
________
22
316 '009140' '9140' '9139' '009139' '002484' '2484') then ficecode='009137';
_
22
200
ERROR: File WORK.IF.DATA does not exist.
ERROR: File WORK.FICECODE.DATA does not exist.
ERROR: File WORK.THEN.DATA does not exist.
ERROR: File WORK.FICECODE.DATA does not exist.
ERROR: The value '009137'n is not a valid SAS name.
ERROR 22-7: Invalid option name '009137'.

ERROR 22-322: Syntax error, expecting one of the following: a name, a quoted string, (, -, :,
;, END, INDSNAME, KEY, KEYS, NOBS, OPEN, POINT, _DATA_, _LAST_, _NULL_.

ERROR 200-322: The symbol is not recognized and will be ignored.


How can I tell SAS if & then are not files?