ALV - CL_SALV_TABLE - layout

hi

i want to know how can i do the following things in alv class CL_SALV_TABLE:

P_GS_LAYOUT-TOTALS_BEFORE_ITEMS = 'X'.

P_GS_LAYOUT-COLWIDTH_OPTIMIZE = 'X'.

P_GS_LAYOUT-GROUP_BUTTONS = 'X'.

P_GS_LAYOUT-BOX_FIELDNAME = 'X'.

thanks

have a nice day