nothing is being displayed in my gridview

Hi nothing is being displayed in my gridview when i try this:

   protected void Button2_Click(object sender, EventArgs e)
    {
        string FirstName = TextBox2.Text;
        SqlDataSource1.SelectCommand = "SELECT FirstName, SecondName FROM User WHERE FirstName LIKE '%" + FirstName + "%'";

        GridView1.DataBind();
    }
}

my sqldatasource is bound to a odbc connection string so I can connect to a mysql database asp:

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder2" Runat="Server">
    <asp:SqlDataSource ID="SqlDataSource1" runat="server" 
        ConnectionString="<%$ ConnectionStrings:ODBCDataConnectionString %>" 
        ProviderName="<%$ ConnectionStrings:ODBCDataConnectionString.ProviderName %>" 
        SelectCommand="SELECT FirstName, SecondName FROM User WHERE Fi开发者_StackOverflow社区rstName LIKE '%' + @qsFirstName + '%'">
        <SelectParameters>
        <asp:QueryStringParameter Name="qsFirstName" QueryStringField="firstname" />
        </SelectParameters>
    </asp:SqlDataSource>
    <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
    <asp:Button ID="Button2" runat="server" onclick="Button2_Click" Text="Button" />
    <asp:GridView ID="GridView1" runat="server" DataSourceID="SqlDataSource1" 
        EnableModelValidation="True">
    </asp:GridView>
</asp:Content>

What is the value of the select command after you build it?

SqlDataSource1.SelectCommand = "SELECT FirstName, SecondName FROM User WHERE FirstName LIKE '%" + FirstName + "%'";

Does FirstName have any trailing spaces?