public bool ValidateUser(string userName, string password)
 {
     if (String.IsNullOrEmpty(userName)) throw new ArgumentException("Value cannot be null or empty.", "userName");
     if (String.IsNullOrEmpty(password)) throw new ArgumentException("Value cannot be null or empty.", "password");
     var db = new foodAppEntities();
     List<User_acc> user = db.User_acc.Where(n => n.name == userName && n.password == password).Select(n => n).ToList();
     if (user.Count != 1)
     {
         db.Dispose();
         return false;
     }
     else
     {
         db.Dispose();
         return true;
     }
 }
 public bool changePass(string name,string oldPass,string newPass)
 {
     foodAppEntities db = new foodAppEntities();
     List<User_acc> user = db.User_acc.Where(n => n.name == name && n.password == oldPass)
         .Select(n => n).ToList();
     if (user.Count != 1)
         throw new ArgumentException("too many or two few entries with that username", "name");
     user.FirstOrDefault().password = newPass;
     db.SaveChanges();
     db.Dispose();
     return true;
 }
 public MembershipCreateStatus makeUser(string name, string password, int? number)
 {
     MembershipCreateStatus myStatus = MembershipCreateStatus.Success;
     foodAppEntities db = new foodAppEntities();
     User_acc myacc = new User_acc();
     List<User_acc> mylist = db.User_acc
         .Where(n=>(n.number == number)&&(String.IsNullOrEmpty(n.name)||(n.name == name)))
         .Select(n=>n).ToList();
     if( mylist.Count > 0)
         return MembershipCreateStatus.DuplicateUserName;
     myacc.number = number.Value;
     myacc.name = name;
     myacc.password = password;
     db.AddToUser_acc(myacc);
     db.SaveChanges();
     db.Dispose();
     return myStatus;
 }