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 brugernav ...