how to view two table datas into one gridview.....

<asp:GridView ID="GridView1" runat="server" AllowPaging="True" PageSize="4" AutoGenerateColumns="False"
        BackColor="White" BorderColor="#CCCCCC" BorderStyle="Ridge" BorderWidth="2px"
        CellPadding="3" DataKeyNames="ReplyDoubtID" DataSourceID="SqlDataSource1" OnRowCommand="GridView1_RowCommand"
        CssClass="roundedbox" CellSpacing="1" GridLines="None">
        <Columns>
            <asp:BoundField DataField="Name" HeaderText="Sender Name" SortExpression="Name" />
            <asp:BoundField DataField="Subject" HeaderText="Subject" SortExpression="Subject" />
            <asp:BoundField DataField="Date" HeaderText="Date" SortExpression="Date" />
            <asp:TemplateField HeaderText="Topic">
                <ItemTemplate>
                    <asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("Topic") %>' TextMode="MultiLine"
                        Height="54px" Width="202px" CssClass="roundedbox"></asp:TextBox>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="Solved Doubts">
                <ItemTemplate>
                    <asp:TextBox ID="TextBox2" runat="server" Text='<%# Bind("ReplyDoubt") %>' TextMode="MultiLine"
                        Height="84px" Width="239px" CssClass="roundedbox"></asp:TextBox>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="Download">
                <ItemTemplate>
                    <asp:LinkButton ID="LinkButton1" runat="server" CommandArgument='<%# Eval("Files") %>'
                        Text='<%# Eval("Files") %>' CommandName="Download" OnClick="LinkButton1_Click"></asp:LinkButton>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="Rate">
                <ItemTemplate>
                    <cc1:Rating ID="Rating1" runat="server" StarCssClass="Star" WaitingStarCssClass="WaitingStar"
                        EmptyStarCssClass="Star" FilledStarCssClass="FilledStar" Height="22px" Width="107px"
                        AutoPostBack="True" OnChanged="OnRatingChanged" BehaviorID="Rating1_RatingExtender">
                    </cc1:Rating>
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
        <FooterStyle BackColor="White" ForeColor="#000066" />
        <HeaderStyle BackColor="#006699" Font-Bold="True" ForeColor="White" />
        <PagerStyle BackColor="White" ForeColor="#000066" HorizontalAlign="Left" />
        <RowStyle ForeColor="#000066" />
        <SelectedRowStyle BackColor="#669999" Font-Bold="True" ForeColor="White" />
        <SortedAscendingCellStyle BackColor="#F1F1F1" />
        <SortedAscendingHeaderStyle BackColor="#007DBB" />
        <SortedDescendingCellStyle BackColor="#CAC9C9" />
        <SortedDescendingHeaderStyle BackColor="#00547E" />
    </asp:GridView>
    <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:VCRConnectionString %>"
        SelectCommand="SELECT * FROM [ReplyDoubt]" FilterExpression="Topic LIKE '%{0}%'">
        <FilterParameters>
            <asp:ControlParameter Name="Topic" ControlID="TextBox3" PropertyName="Text" />
        </FilterParameters>
    </asp:SqlDataSource>
</asp:Content>