Hi Selva,
Design the smartform which you want. After that in the ALV we have one parameter USER_COMMAND
In that we want to write the logic as below.
Form user_command using v_ucomm type sy-ucomm
wa_selfield type slis_selfield.
Case : wa_selfied-value.
when 'EBELN' " say for example
Call the Smartform here by calling its FM.(The FM which you got after activating the smartform).
endcase.
endform.
Hope this helps you.
Thanks
Pavan.N