how to change the layout-urgent

Hi,

i have a requirement i displayed output BY using ALV List Display .Iam displaying quarter ,year,sales group,site(kunnr),amount,etc in in li list disply. now my requirement is when i click sort(Ascending or descending) and select the fileds as sales group,site,quarter then it has to display output in that format.

any body can send the sample code plz.

its very urgent.