Database Connectivity with C# Application

try
            {
                DataSet ds=new DataSet();
                connection.Open();
                cmd = new SqlCommand();
                cmd.Connection = connection;
                dadapter = new SqlDataAdapter();
                dadapter.InsertCommand= connection.CreateCommand();
                dadapter.InsertCommand.CommandText = "insert into contacts (CName,CNumber,Address) values(@CName,@Number,@Address)";
                cmd.Parameters.AddWithValue("@CName", textBox1.Text);
                cmd.Parameters.AddWithValue("@CNumber",textBox2.Text);
                cmd.Parameters.AddWithValue("@Address",textBox3.Text);
            
                MessageBox.Show("Record Saved", "Done", MessageBoxButtons.OK, MessageBoxIcon.Information);
                textBox1.Clear();
                textBox2.Clear();
                textBox3.Clear();
                connection.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }