how to prevent postback when using gridview control.

I am using a gridview control with a button inside it so when i click on the button of the last record it automatically goes to the first record how to prevent the postback from firing :
<asp:ButtonField ButtonType="Button" CommandName="ProdBtn" Text="Products View"> <ControlStyle BackColor="#99CCFF" Font-Names="Calibri" /> </asp:ButtonField>
but when i select the last record in the gridview the gridview gets refreshed and the record selector goes to the top.
HOw to prevent the post back of the gridview..