my code is executing but data is not get inserted in table

[rituja patil]

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
 
namespace testing
{
    public partial class Form1 : Form
    {
        string connection=("Data Source=.\\SQLEXPRESS;AttachDbFilename=|DataDirectory|\\testing.mdf;Integrated Security=True;User Instance=True");
        //string conn = System.Configuration.ConfigurationSettings.AppSettings["DBConn"];
        SqlConnection con;
        SqlCommand cmd;
        string qry = "";
        public Form1()
        {
            InitializeComponent();
        }private void Form1_Load(object sender, EventArgs e)
        {
            // TODO: This line of code loads data into the 'testingDataSet1.testing' table. You can move, or remove it, as needed.
            this.testingTableAdapter.Fill(this.testingDataSet1.testing);
 
        }
 
        private void button1_Click_1(object sender, EventArgs e)
        {
string first = textBox3 .Text ;  
 
             string last = textBox4 .Text ;  
            qry = "insert into testing(col1,col2) values(@first,@last)";//('" +  textBox3 .Text  + "','" +  textBox4 .Text  + " ')";
            con = new SqlConnection(connection);
            cmd = new SqlCommand(qry, con);
             cmd .Parameters.AddWithValue ("@first", first);  
            cmd.Parameters.AddWithValue("@last", last);
            cmd.Connection = con;
            if (con.State == ConnectionState.Open)
                con.Close();
            else
                con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
            MessageBox.Show("Recored is inserted");
        }

[hikmetrza]

chech this version:

qry="insert into test(col1,col2) values ("+textbox3.text+","+textbox4.text+")"
cmd = new SqlCommand(qry,con);
cmd.ExecuiteNonQuery();

in my project this sample code nice work. i am not using Parametrs() metod in cmd.