warning message (code not find)

Question

Hello!

 

My codes are working well without problem. What I need? I would like to have a warning message when the code was not find. Where can I put it and how to write thse codes. 

 

 

private void btnfindcod_Click(object sender, EventArgs e)

{

string connectionString = @"Data Source=localhost\sqlexpress;Initial Catalog=master;Integrated Security=True";

SqlConnection sqlCon = new SqlConnection(connectionString);

sqlCon.Open();

string commandString = "select * from company where code ='" + txtcode.Text + "'";

SqlCommand sqlCmd = new SqlCommand(commandString, sqlCon);

SqlDataReader read = sqlCmd.ExecuteReader();

while (read.Read())

{

txtprodut.Text = read["product"].ToString(); 

}

 

// It's probably here or not? ... code not found...

sqlCon.Close();

}