ASP.Net Panel Visible Error: Object reference not set to an instance of an object

Hey micah,

I checked the code is working, So please refer below code.

HTML

<div>
    name:
    <asp:TextBox runat="server" ID="txtName" /><br />
    country:
    <asp:TextBox runat="server" ID="txtCountry" />
    <asp:LinkButton ID="btnsubmit" runat="server" CssClass="btn btn-info btn-circle"
        Height="50px" Width="120px" Font-Bold="True" OnClick="btnsubmit_Click">Save Record</asp:LinkButton>
    <asp:Button ID="btnReset" runat="server" CssClass="btn btn-default btn-circle" Text="Refresh"
        Height="50px" Width="100px" Font-Bold="True" OnClick="btnReset_Click" />
    <asp:Label ID="Label6" runat="server"></asp:Label>
    <div class=" text-right" style="">
        <asp:Panel ID="Panel2" runat="server" Font-Size="Large" Visible="false">
            <asp:Label ID="lblMessage2" runat="server" Text="" CssClass="alert alert-danger alert-dismissable"></asp:Label>
        </asp:Panel>
    </div>
</div>

Namespaces

C#

using System.Data.SqlClient;
using System.Configuration;
using System.Data;

Code

C#

protected void btnsubmit_Click(object sender, EventArgs e)
{
    int inserted = 0;
    string str = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection())
    {
        con.ConnectionString = str;
        using (SqlCommand cmd = new SqlCommand())
        {
            cmd.CommandType = CommandType.Text;
            cmd.Connection = con;
            cmd.CommandText = "INSERT INTO Customers (Name,Country) VALUES(@Name,@Country)";
            cmd.Parameters.AddWithValue("@Name", txtName.Text);
            cmd.Parameters.AddWithValue("@Country", txtCountry.Text);
            con.Open();
            inserted = cmd.ExecuteNonQuery();
            con.Close();
            Panel2.Visible = true;
            string message = string.Empty;
            {
                lblMessage2.Visible = true;
                lblMessage2.Text = "Data Submitted Successfully";
            }
        }
    }
}

protected void btnReset_Click(object sender, EventArgs e)
{
    txtName.Text = "";
    txtCountry.Text = "";
}

Screenshot