public IList<User> GetAllUsers()
 {
     IList<User> list = null;
     using (UserDataContext context = new UserDataContext(UserDataContext.DBConnectionString))
     {
         IQueryable<User> query = from c in context.User select c;
         list = query.ToList();
     }
     return list;
 }
 public void AddUser(String Username, String Password)
 {
     using (UserDataContext context = new UserDataContext(UserDataContext.DBConnectionString))
     {
         User du = new User();
         du.user_name = Username;
         du.user_pass = Password;
         context.User.InsertOnSubmit(du);
         context.SubmitChanges();
     }
 }