can't invoke function (PL/SQL)

I compiled the function below in Oracle for Win95

CREATE OR REPLACE FUNCTION IsNumeric( C IN CHAR ) RETURN BOOLEAN IS
BEGIN
        RETURN ( C >= '0' AND C <= '9' );
END; I verified it with ...

SELECT object_type, object_name,status
FROM user_objects
WHERE object_type = 'FUNCTION'

--> valid !

I did a

SELECT IsNumeric('p') FROM DUAL;

and got an error: no such column ... or similar...

WHY? Received on Thu Apr 03 1997 - 00:00:00 CST