ABAP Programs: Using interface parameters of a form

REPORT ZSOURCE1004
* Types and data for later use
TYPES: T_NAME(20).
DATA: NAME_1 TYPE T_NAME VALUE ‘A’,
NAME_2 TYPE T_NAME VALUE ‘B’.
* Calling a form with different parameters
PERFORM SET_NAME CHANGING NAME_1.
PERFORM SET_NAME CHANGING NAME_2.
* Defining a form with a parameter
FORM SET_NAME
CHANGING F_NAME TYPE T_NAME.
WRITE F_NAME.
F_NAME = ‘Smith’.
WRITE F_NAME.
ENDFORM.