Parameters as DropDown in Selection Screen

TYPE-POOLS: VRM.

DATA: NAME  TYPE VRM_ID,
      LIST  TYPE VRM_VALUES,
      VALUE LIKE LINE OF LIST.

PARAMETERS: PS_PARM(10) AS LISTBOX VISIBLE LENGTH 10.

AT SELECTION-SCREEN OUTPUT.

NAME = 'PS_PARM'.

VALUE-KEY = 'vinoth'.
VALUE-TEXT = '1'.
APPEND VALUE TO LIST.

VALUE-KEY = 'Dinesh'.
VALUE-TEXT = '2'.
APPEND VALUE TO LIST.

CALL FUNCTION 'VRM_SET_VALUES' EXPORTING ID = NAME VALUES = LIST.

START-OF-SELECTION.
WRITE: / 'PARAMETER:', PS_PARM.