Forms - Master-Details relationship problem

[Quoted] I have the following tables. I want to have a result :

  Whenever a customer is displayed, all corresponding   rentals records together with all corresponding   movie details record will be listed.

In the form,I built 4 data blocks. I have tried to create the master-detail relationship for each of the block. In the canvas, I had the customers, rentals and the movies blocks displayed.

However, when I do execute_query, the movies block is empty and I got the following error message:

  FRM-40106: No navigable items in destination block.

Any help, form expert, please?

SQL> desc customers; (One customer can have many rentals)

 Name                            Null?    Type


 ------------------------------- -------- ----

 ID                              NOT NULL NUMBER
 LAST_NAME                       NOT NULL VARCHAR2(30)
 FIRST_NAME                      NOT NULL VARCHAR2(30)
 STATUS                                   CHAR(1)

SQL> desc rentals; (One rental per tape)
 Name                            Null?    Type


 ------------------------------- -------- ----

 CUSTOMER_ID                     NOT NULL NUMBER
 TAPE_ID                         NOT NULL NUMBER
 RENT_DT                         NOT NULL DATE
 RETURN_DT                                DATE
 DAILY_RATE                               NUMBER(4,2)

SQL> desc tapes; (One tape can have one movie)
 Name                            Null?    Type


 ------------------------------- -------- ----

 ID                              NOT NULL NUMBER
 MOVIE_ID                                 NUMBER
 STATUS                                   CHAR(1)

SQL> desc movies;
 Name                            Null?    Type


 ------------------------------- -------- ----

 ID                              NOT NULL NUMBER
 TITLE                           NOT NULL VARCHAR2(30)
 STATUS                                   CHAR(1)
 ACTOR                                    VARCHAR2(30)
 ACTRESS                                  VARCHAR2(30)
 PRODUCER                                 VARCHAR2(30)
 RATING                                   CHAR(1)