Trying to call a user-defined function from Forms 4.0.12 - Problems - Is this an Oracle bug?

Hello,

I have a user-defined SQL function, preferred_name. Here is it's header file

Create Or Replace Function      Preferred_Name
                (
                Card_Year               In      Natural         Default Null,
                Card_Maniple            In      Natural         Default Null,
                Card_Number             In      Natural         Default Null,
                Title_Abbreviation      In      VarChar2        Default Null,
                First_Forename          In      VarChar2        Default Null,
                Middlename              In      VarChar2        Default Null,
                Preferred_Forename      In      VarChar2        Default Null,
                Surname                 In      VarChar2        Default Null,
                Prefer_Title            In      Char            Default Null,
                Prefer_Initials         In      Char            Default Null,
                Prefer_Fullstops        In      Char            Default Null,
                Prefer_Middle_Names     In      Char            Default Null,
                Format                  In      Natural         Default 0
                )
                Return  VarChar2        Is

It can be called from sqlplus with no-parameters or parameters as follows

SQL> select preferred_name from dual;

PREFERRED_NAME

SQL> select csv_user_oracle.preferred_name('','','','Mr','Richard','James','Rich', 'Tinker','N','N','N','N') from dual;

CSV_USER_ORACLE.PREFERRED_NAME('','','','MR','RICHARD','JAMES','RICH','TINKER','

I am experiencing problems trying to call this function from an Oracle Form (version 4.0.12). I am trying to call the function from a trigger in Forms and assign the result to a variable. The function is in the schema csv_user_oracle, and my personal schema is csv_user_esuvl.  

select csv_user_oracle.preferred_name('','','','Mr','Richard','James', 'Rich','Tinker','N','N','N','N') into function_result from dual;

OR

function_result := preferred_name();

When compiling the trigger, Oracle Forms gives the following error

Error 302 at line 66, column 24
 component 'PREFERRED_NAME' must be declared

If I try and call the function as:

function_result := preferred_name();

where function_result is declared as VARCHAR2 I also get the same error.

I have tried declaring the function in various ways but this fails. (I think the declaring of a function message my be a red herring because I use a function in another PL/SQL block of code without declaring it

 Forenames := Initialise (Forenames);

where Initialise is another function. Does anyone know what I have done wrong. Is this a bug in Oracle Forms version 4.0.12. I'm sure that calling a function from a trigger is a fairly normal thing to do.

Help.

Richard Tinker

--
R.J.Tinker_at_csv.warwick.ac.uk