searching name from database using textbox in windows application

try
                {
                    con = new MySqlConnection();
                    con.ConnectionString = ConfigurationSettings.AppSettings["constr"];
                    con.Open();
                    string str = "select pfno,name,desig,oldtno,newtno from empreg where name like " + textBox1.Text;
                    da = new MySqlDataAdapter(str, con);
                    ds = new DataSet();
                    da.Fill(ds, "empreg");
                    dataGridView1.DataSource = ds.Tables[1];
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
                finally
                {
                    con.Close();
                }