SELECT ROWS LIKE ...ENTERED IN TEXTBOX

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.OleDb;
namespace Search
{
    public partial class Form1 : Form
    {
        string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["dsn"];
        OleDbCommand com;
        OleDbDataAdapter oledbda;
        DataSet ds;
        string str;
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            OleDbConnection con = new OleDbConnection(ConnectionString);
            con.Open();
            str = "select * from student where hno like '" + textBox1.Text + "%'";
            com = new OleDbCommand(str, con);
            oledbda = new OleDbDataAdapter(com);
            ds = new DataSet();
            if (Convert.ToBoolean(oledbda.Fill(ds, ("student"))))
            {
                dataGridView1.DataSource = ds;
                dataGridView1.DataMember = "student";
                MessageBox.Show("match found");
            }
            else
            {
                MessageBox.Show("match not found");

            }
            con.Close();
        }
    }
}