custom screen is not appearing as a pop up

Hi

I have a requirement that on MM01/02 save, a custom screen should be shown with a table control and few buttons.

I have created the screen and also is able to display it after save, however its not coming as a POP up screen.

1> I have the properties set as MODAL dialog box of the screen

2> I have also specified as CALL SCREEN ..STARTING AS ENDING AS..

still the output comes as a ONE normal screen with the a SAP background screen, Please can someone help.  Attaching the screen

regards

SB