Displaying SQL Data in a Text Box Using C# [Code Snippet]

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 RetrieveData {
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            }
        private void button1_Click(object sender, EventArgs e)
        {
            bool temp = false;
            SqlConnection con = new SqlConnection("server=arun\\SQLEXPRESS;database=pan;Trusted_Connection=True");
            con.Open();
            SqlCommand cmd = new SqlCommand("select * from Table2 where first='" + textBox1.Text.Trim() + "'", con);
            SqlDataReader dr = cmd.ExecuteReader();
            while (dr.Read())
            {
                textBox2.Text = dr.GetString(1);
                textBox3.Text = dr.GetString(2);
                temp = true;
                }
            if (temp == false)
            MessageBox.Show("not found");
            con.Close();
            }
        }
    }