Display Row total in footer of gried

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" BackColor="White"
        BorderColor="#336699" BorderStyle="Solid" BorderWidth="1px" CellPadding="2" Font-Names="Verdana"
        ShowFooter="true" Font-Size="10pt" Width="50%"  GridLines="Horizontal"
        OnRowDataBound="GridView1_RowDataBound">
        <Columns>
             <asp:TemplateField HeaderText="Date">
                <ItemTemplate>
                    <asp:Label ID="lblPrice" runat="server" Text='<%# Eval("date")%>' />
                </ItemTemplate>
                <FooterTemplate>
                    <asp:Label ID="lblTotalPrice" runat="server" />
                </FooterTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="salary">
                <ItemTemplate>
                    <asp:Label ID="lblUnitsInStock" runat="server" Text='<%# Eval("sal") %>' />
                </ItemTemplate>
                <FooterTemplate>
                    <asp:Label ID="lblTotalUnitsInStock" runat="server" />
                    <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
                </FooterTemplate>
            </asp:TemplateField>
        </Columns>
        <FooterStyle BackColor="#336699" Font-Bold="True" ForeColor="White" HorizontalAlign="Left" />
      
        <HeaderStyle BackColor="#336699" Font-Bold="True" ForeColor="White" HorizontalAlign="Left" />
    </asp:GridView>




 private void BindData()
    {
        SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS;Initial Catalog=anil;Integrated Security=True");

        string query = "SELECT * FROM anil";

        SqlDataAdapter da = new SqlDataAdapter(query, con);
        DataTable table = new DataTable();

        da.Fill(table);

        GridView1.DataSource = table;
        GridView1.DataBind();
    }



    protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {

        SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS;Initial Catalog=anil;Integrated Security=True");

        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            tsals += Convert.ToDecimal(DataBinder.Eval(e.Row.DataItem, "sal"));

        }
        if (e.Row.RowType == DataControlRowType.Footer)
        {
            e.Row.Cells[1].Text = String.Format("{0:c}", tsals);
        }
    }