f30 and stored function

I've created a stored function wich works properly used from sqlplus like

select function_name(arguments) from sys.dual;

but when I try tu use the same statement like

select function_name(:field1, :field2) into :field3 from sys.dual;

f30 says indentifier 'function_name' should be declared! liek it does not recognise my
stored function. (the same user as in sqlplus)

WHERE DO I DECLARE IT?? Thanks... Received on Tue May 25 1999 - 15:02:12 CEST