datagrid control

I have a grid in my content holder.

This grid binds with some database values on page load. one value field is "Status". Its a dropdownlist. now i need to add 'Submit' a button on this page to edit the rows. user can change the status of any row and he will click the button once to edit all the changed the rows. how do i do this with this grid. how do i read the values of dorpdown list of each row. how should i write my loop to read each row of this grid.

Thanks

Read through these articles, very good stuff.
http://aspnet.4guysfromrolla.com/articles/121504-1.aspx