<asp:GridView ID="GridView1" runat="server" AllowPaging="True"

            AllowSorting="True" OnSelectedIndexChanged="GridView1_SelectedIndexChanged"

            DataMember="DefaultView" BackColor="#C0C0FF" AutoGenerateColumns="False" DataSourceID="SqlDataSource1">

            <Columns>

                <asp:CommandField ShowSelectButton="True"></asp:CommandField>

                <asp:BoundField HeaderText="StudentID" DataField="StudentID" SortExpression="StudentID">

                </asp:BoundField>

                <asp:BoundField HeaderText="StudentName" DataField="StudentName" SortExpression="StudentName">

                </asp:BoundField>

            </Columns>

        </asp:GridView>

        <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ExForSysConnectionString2 %>"

            SelectCommand="SELECT DISTINCT [StudentID], [StudentName] FROM [StudentMaster]">

        </asp:SqlDataSource>

        &nbsp;&nbsp;&nbsp;