Hello experts..

I am using Oracle9i in server and in client using visual basic. I m using
Microsoft ADO OLEDB (SP2) for connectivity. but i need...

i have a table :

student

Id name
-- -----
1 AAA
2 BBB
3 CCC

now Client a want to update AAA - > A111 where Id = 1 at Time: 8:00 PM
and
Client b want to same record AAA - > A222 where Id = 1 at Time: 8:10 PM

now i want to prevent Client B from updating...when A save that record than B can do update.

Plz help me i m in grt problem...