diff --git a/flutter_base/lib/mobx/form/form_store.dart b/flutter_base/lib/mobx/form/form_store.dart
index 6f39e91..219b50c 100644
--- a/flutter_base/lib/mobx/form/form_store.dart
+++ b/flutter_base/lib/mobx/form/form_store.dart
@@ -41,7 +41,7 @@ abstract class _FormStore with Store {
 
   @action
   void validateEmail(String value) {
-    error.email = isEmail(value) ? 'Not a valid email' : null;
+    error.email = !isEmail(value) ? 'Not a valid email' : null;
   }
 
   @action
@@ -65,7 +65,6 @@ abstract class _FormStore with Store {
       error.username = null;
     }
 
-    error.username = null;
   }
 
   Future<bool> checkValidUsername(String value) async {
diff --git a/flutter_base/lib/my_form_bloc/main.dart b/flutter_base/lib/my_form_bloc/main.dart
new file mode 100644
index 0000000..24a9d56
--- /dev/null
+++ b/flutter_base/lib/my_form_bloc/main.dart
@@ -0,0 +1,119 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+
+import 'my_form_bloc.dart';
+
+void main() {
+  runApp(const MyApp());
+}
+
+class MyApp extends StatelessWidget {
+  const MyApp({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      home: BlocProvider<MyFormBloc>(
+        create: (context) => MyFormBloc(),
+        child: const AppForm(),
+      ),
+    );
+  }
+}
+
+class AppForm extends StatelessWidget {
+  const AppForm({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    final _bloc = context.read<MyFormBloc>();
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('Signup form'),
+      ),
+      body: Form(
+        child: Padding(
+          padding: const EdgeInsets.all(10),
+          child: Column(
+            children: [
+              BlocBuilder<MyFormBloc, MyFormState>(
+                bloc: _bloc,
+                builder: (context, state) {
+                  return TextField(
+                    onChanged: (value) {
+                      _bloc.add(UsernameChanged(value));
+                    },
+                    decoration: InputDecoration(
+                      labelText: 'Username',
+                      hintText: 'Pick a username',
+                      errorText: state.errorUsername,
+                    ),
+                  );
+                },
+              ),
+              BlocBuilder<MyFormBloc, MyFormState>(
+                bloc: _bloc,
+                builder: (context, state) {
+                  return AnimatedOpacity(
+                      duration: const Duration(milliseconds: 300),
+                      opacity: state.isUsernameCheck ? 1 : 0,
+                      child: const LinearProgressIndicator());
+                },
+              ),
+              BlocBuilder<MyFormBloc, MyFormState>(
+                bloc: _bloc,
+                builder: (context, state) {
+                  return TextField(
+                    onChanged: (value) {
+                      _bloc.add(EmailChanged(value));
+                    },
+                    keyboardType: TextInputType.emailAddress,
+                    decoration: InputDecoration(
+                      labelText: 'Email',
+                      hintText: 'Enter your email address',
+                      errorText: state.errorEmail,
+                    ),
+                  );
+                },
+              ),
+              BlocBuilder<MyFormBloc, MyFormState>(
+                bloc: _bloc,
+                builder: (context, state) {
+                  return TextField(
+                    onChanged: (value) {
+                      _bloc.add(PasswordChanged(value));
+                    },
+                    decoration: InputDecoration(
+                        labelText: 'Password',
+                        hintText: 'Set a password',
+                        errorText: state.errorPassword
+                    ),
+                  );
+                },
+              ),
+              BlocBuilder<MyFormBloc, MyFormState>(
+                bloc: _bloc,
+                builder: (context, state) {
+                  return ElevatedButton(
+                    onPressed: () {
+                      _bloc.add(FormSubmitted());
+                      if (state.noErrors) {
+                        ScaffoldMessenger.of(context)
+                          ..hideCurrentSnackBar()
+                          ..showSnackBar(
+                            const SnackBar(
+                                content: Text('Registration Success')),
+                          );
+                      }
+                    },
+                    child: const Text('Sign up'),
+                  );
+                },
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
diff --git a/flutter_base/lib/my_form_bloc/my_form_bloc.dart b/flutter_base/lib/my_form_bloc/my_form_bloc.dart
new file mode 100644
index 0000000..f25a059
--- /dev/null
+++ b/flutter_base/lib/my_form_bloc/my_form_bloc.dart
@@ -0,0 +1,174 @@
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:validators2/validators.dart';
+
+abstract class MyFormEvents {}
+
+class UsernameChanged extends MyFormEvents {
+  final String username;
+
+  UsernameChanged(this.username);
+}
+
+class EmailChanged extends MyFormEvents {
+  final String email;
+
+  EmailChanged(this.email);
+}
+
+class PasswordChanged extends MyFormEvents {
+  final String password;
+
+  PasswordChanged(this.password);
+}
+
+class FormSubmitted extends MyFormEvents {}
+
+class MyFormState {
+  final String username;
+  final String? errorUsername;
+  final String email;
+  final String? errorEmail;
+  final String password;
+  final String? errorPassword;
+  final bool isUsernameCheck;
+
+  MyFormState({
+    required this.username,
+    required this.errorUsername,
+    required this.email,
+    required this.errorEmail,
+    required this.password,
+    required this.errorPassword,
+    required this.isUsernameCheck,
+  });
+
+  MyFormState copyWith({
+    String? username,
+    String? errorUsername,
+    String? email,
+    String? errorEmail,
+    String? password,
+    String? errorPassword,
+    bool? isUsernameCheck,
+  }) {
+    return MyFormState(
+      username: username ?? this.username,
+      errorUsername: errorUsername,
+      email: email ?? this.email,
+      errorEmail: errorEmail,
+      password: password ?? this.password,
+      errorPassword: errorPassword,
+      isUsernameCheck: isUsernameCheck ?? this.isUsernameCheck,
+    );
+  }
+
+  bool get noErrors =>
+      username.isNotEmpty &&
+      errorUsername == null &&
+      email.isNotEmpty &&
+      errorEmail == null &&
+      password.isNotEmpty &&
+      errorPassword == null;
+}
+
+class MyFormBloc extends Bloc<MyFormEvents, MyFormState> {
+  MyFormBloc()
+      : super(MyFormState(
+          username: '',
+          errorUsername: null,
+          email: '',
+          errorEmail: null,
+          password: '',
+          errorPassword: null,
+          isUsernameCheck: false,
+        )) {
+    on<UsernameChanged>(_onUsernameChanged);
+    on<EmailChanged>(_onEmailChanged);
+    on<PasswordChanged>(_onPasswordChanged);
+    on<FormSubmitted>(_onFormSubmitted);
+  }
+
+  void _onUsernameChanged(
+      UsernameChanged event, Emitter<MyFormState> emit) async {
+    emit(state.copyWith(
+      username: event.username,
+      errorUsername: _checkUsername(event.username),
+      errorEmail: state.errorEmail,
+      errorPassword: state.errorPassword,
+    ));
+
+    try {
+      emit(state.copyWith(
+        errorUsername: state.errorUsername,
+        errorEmail: state.errorEmail,
+        errorPassword: state.errorPassword,
+        isUsernameCheck: true,
+      ));
+      final _isValid = await _checkValidUsername(event.username);
+      emit(state.copyWith(
+        errorUsername: state.errorUsername,
+        errorEmail: state.errorEmail,
+        errorPassword: state.errorPassword,
+        isUsernameCheck: false,
+      ));
+      if (!_isValid) {
+        emit(state.copyWith(
+          username: event.username,
+          errorUsername: 'Username cannot be "admin"',
+          errorEmail: state.errorEmail,
+          errorPassword: state.errorPassword,
+        ));
+        return;
+      }
+    } catch (_) {
+      emit(state.copyWith(
+        errorUsername: null,
+        errorEmail: state.errorEmail,
+        errorPassword: state.errorPassword,
+      ));
+    }
+  }
+
+  void _onEmailChanged(EmailChanged event, Emitter<MyFormState> emit) =>
+      emit(state.copyWith(
+        errorUsername: state.errorUsername,
+        email: event.email,
+        errorEmail: _checkEmail(event.email),
+        errorPassword: state.errorPassword,
+      ));
+
+  void _onPasswordChanged(PasswordChanged event, Emitter<MyFormState> emit) =>
+      emit(state.copyWith(
+        errorUsername: state.errorUsername,
+        errorEmail: state.errorEmail,
+        password: event.password,
+        errorPassword: _checkPassword(event.password),
+      ));
+
+  void _onFormSubmitted(FormSubmitted event, Emitter<MyFormState> emit) {
+    emit(state.copyWith(
+      errorUsername: state.username.isEmpty
+          ? _checkUsername(state.username)
+          : state.errorUsername,
+      errorEmail: _checkEmail(state.email),
+      errorPassword: _checkPassword(state.password),
+    ));
+  }
+
+  String? _checkUsername(String username) {
+    return isNull(username) ? 'Field is required' : null;
+  }
+
+  Future<bool> _checkValidUsername(String value) async {
+    await Future.delayed(const Duration(seconds: 1));
+    return value != 'admin';
+  }
+
+  String? _checkEmail(String email) {
+    return !isEmail(email) ? 'Not a valid email' : null;
+  }
+
+  String? _checkPassword(String password) {
+    return isNull(password) ? 'Field is required' : null;
+  }
+}