Gridview not responding

Hi everyone, I have this grid view inside a tab container which is not responding. Can some one please take a look at my code and help me out? Thanks

<div style="width: 100%">

<ajaxToolkit:TabContainer ID="TabContainer1" runat="server" ActiveTabIndex="0"

Width="100%" OnDemand="true" Font-Bold="True" ScrollBars="Auto" AutoPostBack="True" BorderStyle="None">

<ajaxToolkit:TabPanel runat="server" HeaderText="Over View" ID="TabPanel1" OnDemandMode="Once" ScrollBars="Auto">

<ContentTemplate>

<asp:GridView ID="nfrcGridView" runat="server" Width="1179px" AutoGenerateColumns="False" DataSourceID="TechCenter">

<Columns>

<asp:BoundField DataField="Model" HeaderText="Model" SortExpression="Model" />

<asp:BoundField DataField="GlassPackage" HeaderText="GlassPackage" SortExpression="GlassPackage" />

<asp:BoundField DataField="GlassThickness" HeaderText="GlassThickness" SortExpression="GlassThickness" />

<asp:BoundField DataField="Description" HeaderText="Description" SortExpression="Description" />

<asp:BoundField DataField="UFactor" HeaderText="UFactor" SortExpression="UFactor" />

<asp:BoundField DataField="SHGC" HeaderText="SHGC" SortExpression="SHGC" />

<asp:BoundField DataField="VT" HeaderText="VT" SortExpression="VT" />

<asp:BoundField DataField="ER" HeaderText="ER" ReadOnly="True" SortExpression="ER" />

</Columns>

</asp:GridView>

<asp:SqlDataSource ID="TechCenter" runat="server"

ConnectionString="<%$ ConnectionStrings:TechCenterConnectionString %>"

SelectCommand="SELECT Model, GlassPackage, GlassThickness, Description, UFactor, SHGC, VT, ER FROM WindowWorld_Q Where (Model = @Model) and (GlassPackage = @GlassPack)">

<SelectParameters>

<asp:ControlParameter ControlID="ddGlass" Name="GlassPack"

PropertyName="SelectedValue" Type="String" />

<asp:ControlParameter ControlID="ddModel" Name="Model"

PropertyName="SelectedValue" Type="String" />

</SelectParameters>

</asp:SqlDataSource>

</ContentTemplate>

</ajaxToolkit:TabPanel>

And my codebehind is this:   

 protected void ddGlass_SelectedIndexChanged(object sender, EventArgs e)

    {

        nfrcGridView.DataBind();

        Label1.Text = ("You have selected Model " + ddModel.SelectedItem.Text + " From " + ddSeries.SelectedItem.Text + " with " + ddGlass.SelectedItem.Text);

    }

private void BindnfrcGridView()

    {

DataTable dt = new DataTable();

SqlConnection connection = new SqlConnection(GetConnectionString());

    try

        {

string sqlStatement = "SELECT Model, GlassPackage, GlassThickness, Description, UFactor, SHGC, VT, ER FROM WindowWorld_Q Where Model = '” & ddModel.SelectedItem.Text & “' and GlassPackage = '” & ddGlass.SelectedItem.Text &  “'";

SqlCommand sqlCmd = new SqlCommand(sqlStatement, connection);

SqlDataAdapter sqlDa = new SqlDataAdapter(sqlCmd);

            sqlDa.Fill(dt);

         if (dt.Rows.Count > 0)

            {

                nfrcGridView.DataSource = dt;

                ddGlass.DataTextField = ddGlass.SelectedItem.Text;

                ddModel.DataTextField = ddModel.SelectedItem.Text;

                nfrcGridView.DataBind();

            }

        }

catch (System.Exception ex)

        {

            LogError(ex.ToString());

        }

    }

Thanks