Find out about the user's email are available but if not then create a new user with the email.

Hello

it is such that I started making so that you can create user on the website, but I can not really comment on,

it is such that it should find out about the guest's e-mail found in the database because doing it so it must not create user but in fashion if none is found then you have to be sustained in the database.

- Are the use must come up with errors to the page.

- It will not be with some email outcome you should be sustained in the database with the email and the other information you need.

string fejl = "Hov Hov, Du skal læse vore betingelser";

        if(CheckBoxBetingelser.Checked)
        {
            //opretter adgang til databasen.
            SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ToString());
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;

            //Angiver brugernavn skal være med stort!
            string brugernavn = System.Globalization.CultureInfo.CurrentUICulture.TextInfo.ToTitleCase(TextBoxBrugernavn.Text);
            
            //skal finde ud af brugen findes i databasen
            cmd.CommandText = "SELECT Id, brugernavn, rank FROM brugere WHERE brugernavn = @brugernavn";
            cmd.Parameters.AddWithValue("@brugernavn", brugernavn);

            conn.Open();
            SqlDataReader reader = cmd.ExecuteReader();

            if(reader == null)
            {
                //ligger noget sikkert på password
                string adgangskode = MD5.Encrypt(TextBoxAdgangskode.Text);

                string fornavn = TextBoxFornavn.Text;
                string efternavn = TextBoxEfternavn.Text;

                cmd.CommandText = @"INSERT INTO brugere (brugernavn, adgangskode, fornavn, efternavn) 
                VALUES (@brugernavn, @adgangskode, @fornavn, @efternavn);";
                cmd.Parameters.AddWithValue("@brugernavn", brugernavn);
                cmd.Parameters.AddWithValue("@adgangskode", adgangskode);
                cmd.Parameters.AddWithValue("@fornavn", fornavn);
                cmd.Parameters.AddWithValue("@efternavn", efternavn);

                Response.Redirect("login.aspx");
            }
            else
            {
                LabelErrorBesked.Text = "Hov hov, du fik en fejl ved log ind!";
            }
            conn.Close();

        }
        else
        {
            //det er hvis at man ikke har klik på checkbox
            LabelError.Text = fejl;
        }

I'll just say that it is the first time that I work with asp.net when I in the past has worked with php, but is starting on an IT training where my teacher has shown some cool stuff.

I would just build it up like this if it was me but it will be super nice if you could explain to me what I might have to change or do better,

it is such that I am dyslexic and has trouble spelling for some things.

I typed my comment in Danish.