public ActionResult SignUp(Users user)
 {
     if (userLogic.Authentication(user))
     {
         ModelState.AddModelError("Login", "User already existed.");
         ModelState.AddModelError("Password", "User already existed.");
     }
     if (ModelState.IsValid)
     {
         userLogic.Add(user);
         return(RedirectToAction("SignIn"));
     }
     else
     {
         return(View());
     }
 }