How to create a new user name, password, authentication

Hi

How to create a New user using sql server 2005 using c#

i need to create the New user by using the requirements


USERNAME ------------------ TEXTBOX
PASSWORD-------------------TEXTBOX
CONFIRM PASSWORD--------------TEXTBOX
AUTHENTICATIO--------------------COMBOBOX
OK------------------------BUTTON
CANCEL--------------------BUTTON

And if i click on ok it should connect to database and update the new username  and password.........

Please help me regarding this...................

If it is new user registration you can insert the values in database and if the user id already available you can update the values. use bellow code insert values

private void Insert()
{
SqlConnection cn=new SqlConnection("Your String);
SqlCommand cmd=new SqlCommand("Insert Into YourTable(UserName,Password,Authentication)Values('"+txtuname.text+"','"+txtpwd.Text
+"','"+combobox.SelectedItem.Text+"')",cn);
cn.Open();
int _records=cmd.ExecuteNonQuery();
cn.Close();
}

if it is update then change the command like update table set column=value like you can.