update login function

app/Http/Controllers/UserController.php

@@ -26,11 +26,13 @@ public function register(RegisterRequest $request){
 
     public function login(LoginRequest $request){
         $user = User::where('phone', $request->phone)->get();
+        if ($user->count()){
             for ($i = 0; $i < count($user); $i++){
                 if ($user[$i]->password == md5($request->password))
                     return 'Login success';
                 else return 'Login fail';
             } 
+        } else return 'Tai khoan khong ton tai';
     }
 
 }