gridview中的行在更新时不会从现有行替换

I am workin on Leave Management of Employees currently. There is 2 Grid View one for Manager which displays the Leaves Applied by particular Employee that contains ull leave Details. There is Status column in GridView which shows Pending once leave is applied. And once Manager logs in and clicks on Update column which is an Hyperlink he will redirect into another page showing details of the leave and he can Accept or Reject the leave. Once he does any of the two ,gridview will get updated setting status=accepted or rejected from Pending.I am workin on Leave Management of Employees cu