Sorry Max, what I try to implement for this case is this code:
FORM user_command USING r_ucomm LIKE sy-ucomm.
DATA rf_csv TYPE REF TO cl_gui_alv_grid.
IF rf_csv IS INITIAL.
CALL FUNCTION 'GET_GLOBALS_FROM_SLVC_FULLSCR'
IMPORTING
e_grid = rf_csv.
ENDIF.
IF rf_csv IS NOT INITIAL.
CALL METHOD rf_csv->check_changed_data.
ENDIF.
ENDFORM.
But this should be executed by pressing on the button 'TEST'. I made a misstake in my first message.
Or is there better solution to save the changed data in an internal table?
Denis