how to edit and save the records in gridview

hi frnds

i created gridview with dynamically bound field in asp.net ..
i displaying the data from to data base..

now i want in this grid when i edit the perticular row it should be edit and when i click on
save on save button so it should be save in data base

i checked in thei nternet there is showing update the record it self in gridview but i want to update in data base