Visual Studio C ++ формирует множественное включение

Я знаю, что есть много сообщений на эту тему, но все же я не могу заставить его работать.
Я создал новый проект, который называется «NIS».

Это «nis.cpp»:

// nis.cpp : main project file.

#include "stdafx.h"#include "Form1.h"
using namespace nis;

[STAThreadAttribute]
int main(array<System::String ^> ^args)
{
// Enabling Windows XP visual effects before any controls are created
Application::EnableVisualStyles();
Application::SetCompatibleTextRenderingDefault(false);

// Create the main window and run it
Application::Run(gcnew Form1());
return 0;
}

У меня есть две формы.
Это «Form1.h»:

#ifndef FORM1_H
#define FORM1_H
#pragma once
#include "Form2.h"namespace nis {

using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;

/// <summary>
/// Summary for Form1
/// </summary>
public ref class Form1 : public System::Windows::Forms::Form
{
public:
Form1(void)
{
InitializeComponent();
//
//TODO: Add the constructor code here
//
}

protected:
/// <summary>
/// Clean up any resources being used.
/// </summary>
~Form1()
{
if (components)
{
delete components;
}
}
private: System::Windows::Forms::Button^  button1;
protected:

private:
/// <summary>
/// Required designer variable.
/// </summary>
System::ComponentModel::Container ^components;

#pragma region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
void InitializeComponent(void)
{
this->button1 = (gcnew System::Windows::Forms::Button());
this->SuspendLayout();
//
// button1
//
this->button1->Location = System::Drawing::Point(78, 77);
this->button1->Name = L"button1";
this->button1->Size = System::Drawing::Size(144, 53);
this->button1->TabIndex = 0;
this->button1->Text = L"button1";
this->button1->UseVisualStyleBackColor = true;
this->button1->Click += gcnew System::EventHandler(this, &Form1::button1_Click);
//
// Form1
//
this->AutoScaleDimensions = System::Drawing::SizeF(8, 16);
this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
this->ClientSize = System::Drawing::Size(282, 253);
this->Controls->Add(this->button1);
this->Name = L"Form1";
this->Text = L"Form1";
this->Load += gcnew System::EventHandler(this, &Form1::Form1_Load);
this->ResumeLayout(false);

}
#pragma endregion
private: System::Void Form1_Load(System::Object^  sender, System::EventArgs^  e) {
}
private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
this->Hide();
Form2^ f1 = gcnew Form2();
f1->ShowDialog();
}
};
}

#endif

И это «Form2.h»:

#ifndef FORM2_H
#define FORM2_H
#pragma once
#include "Form1.h"namespace nis {

using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;

/// <summary>
/// Summary for Form2
/// </summary>
public ref class Form2 : public System::Windows::Forms::Form
{
public:
Form2(void)
{
InitializeComponent();
//
//TODO: Add the constructor code here
//
}

protected:
/// <summary>
/// Clean up any resources being used.
/// </summary>
~Form2()
{
if (components)
{
delete components;
}
}
private: System::Windows::Forms::Button^  button1;
protected:

private:
/// <summary>
/// Required designer variable.
/// </summary>
System::ComponentModel::Container ^components;

#pragma region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
void InitializeComponent(void)
{
this->button1 = (gcnew System::Windows::Forms::Button());
this->SuspendLayout();
//
// button1
//
this->button1->Location = System::Drawing::Point(44, 102);
this->button1->Name = L"button1";
this->button1->Size = System::Drawing::Size(149, 53);
this->button1->TabIndex = 0;
this->button1->Text = L"button1";
this->button1->UseVisualStyleBackColor = true;
//
// Form2
//
this->AutoScaleDimensions = System::Drawing::SizeF(8, 16);
this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
this->ClientSize = System::Drawing::Size(282, 253);
this->Controls->Add(this->button1);
this->Name = L"Form2";
this->Text = L"Form2";
this->Load += gcnew System::EventHandler(this, &Form2::Form2_Load);
this->ResumeLayout(false);

}
#pragma endregion
private: System::Void Form2_Load(System::Object^  sender, System::EventArgs^  e) {
}
};
}
#endif

Подскажите, пожалуйста, что не так с защитой от включения?
Я получаю эти ошибки:

Error   1   error C2065: 'Form2' : undeclared identifier
d:\users\lior\documents\visual studio 2010\projects\nis\nis\Form1.h 85
Error   2   error C2065: 'f1' : undeclared identifier
d:\users\lior\documents\visual studio 2010\projects\nis\nis\Form1.h 85
Error   3   error C2061: syntax error : identifier 'Form2'
d:\users\lior\documents\visual studio 2010\projects\nis\nis\Form1.h 85
Error   4   error C2065: 'f1' : undeclared identifier
d:\users\lior\documents\visual studio 2010\projects\nis\nis\Form1.h 86
Error   5   error C2227: left of '->ShowDialog' must point to
class/struct/union/generic type d:\users\lior\documents\visual studio
2010\projects\nis\nis\Form1.h   86

Спасибо вам большое!