Hii
do the following,
lx_layout TYPE lvc_s_layo,
lx_layout-sel_mode = 'A'. "Select box
No need to go for the check box
as lx_layout -sel_mode = 'A'. will give u the standard selection of rows.
In your alv grid display u can select what ever the rows u want by keep pressing CTRL button of keyboard.
suppose in grid display there are 5 records. We want to select reocords 1,3.7.10 by pressing CTRL keyboard button and in the same way u can deselect the selected rows by pressing the CTRL button of keyboard.
here is the picture
Reply if it works in your case
Reagrds
syed
Cheers