Hi Vijaya,
In the action of buttons "select all" and "deselect all", we have to loop the table and assign the value of check box as 'X' , modify the table and bind it. Similarly for deselecting, loop the table and assign the value of check box as space and modify the table and bind it.
Please have a look at below code for your ref.
lo_nd_check->get_static_attributes_table( importing table = lt_check ).
LOOP at lt_check into ls_check.
ls_check-CHECKBOX = 'X'.
MODIFY lt_check from ls_check TRANSPORTING checkbox.
ENDLOOP.
Thank you.
Steffi