Oracle Forms

Hi everyone,

I have Forms 6i and one of you colleague have send me the following code to generate Id's and I have insert this code in my program unit

as a Function Body, but when I compile the program I receive the following error:

PDE-PPU017 The program unit source must define a Subprogram Body or Package.

CREATE OR REPLACE FUNCTION generated_id (p_table VARCHAR2) RETURN NUMBER IS
   l_generated_id NUMBER;
   l_table_name VARCHAR2 (30) := UPPER (p_table);
BEGIN
   BEGIN
     SELECT id INTO l_generated_id
        FROM my_table
       WHERE NOMBRE_TABLE = l_table_name
         FOR UPDATE; -- this locks current row


      l_generated_id := l_generated_id + 1;


      UPDATE my_table
         SET id = l_generated_id
       WHERE NOMBRE_TABLA = l_table_name;
   EXCEPTION
      WHEN NO_DATA_FOUND THEN
         l_generated_id := 1;
         INSERT INTO my_table (NOMBRE_TABLA, id)
              VALUES (l_table_name, l_generated_id);
   END;
   RETURN l_generated_id;
END;

Can anyone please help me solve this issue?