dropdown list problem

Question

hello,

i am facing few problems of using dropdown list.

there is a dropdownlist with few items like:- all,abc,def,xyz

my problem is that by default whenever page loads, it shows record for "all", but whenever i just select other item say "abc" or "xyz"; it does not display its respective records in gridview. i just want to select any other item from dropdown and it should have to display its respective record without clicking any button.

and 1 more thing, when the data will display according to dropdown item selection; i can perform edit/delete/add operation only there in gridview.

so please tell me the solution.

thank you.