如何是SELECTION屏幕输入框变成密码输入框

REPORT z_password.

PARAMETERS: p_pass TYPE xuncode.

*---------------------------------------------------------------------*
AT SELECTION-SCREEN OUTPUT.

  LOOP AT SCREEN.
    IF screen-name = 'P_PASS'.
      screen-invisible = '1'.
      MODIFY SCREEN.
    ENDIF.
  ENDLOOP.

*---------------------------------------------------------------------*
START-OF-SELECTION.

  WRITE: / p_pass.