centring controls

  <asp:Panel ID="panel1" BackColor="Silver" BorderStyle="Double" BorderWidth="1" Width="380px"
                Height="150px" runat="server">
                <p>
                    <asp:Label ID="Label2" runat="server" Font-Size="Medium" ForeColor="DarkRed" Width="366px"></asp:Label><br />
                    <br />
                    <br />
                    <asp:Button ID="OkButton" runat="server" Text="Ok"  />&nbsp;</p>
            </asp:Panel>

i have the

i need to cnetre the ok button

asp:Panel is called in modal popup