ทำโปรแกรมแบบ Express เปิดฟอร์มซ้อนกัน เขาทำกันยังไงครับ

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Threading;
using Microsoft.Win32;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        [DllImport("user32.dll")]
        static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);
        [DllImport("user32.dll")]
        static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
        [DllImport("user32.dll")]
        static extern bool MoveWindow(IntPtr Handle, int x, int y, int w, int h, bool repaint);
        private void Form1_Load(object sender, EventArgs e)
        {
            Process p = Process.Start(@"C:\\Windows\\notepad.exe");
            p.WaitForInputIdle();
            SetParent(p.MainWindowHandle, panel1.Handle);    
        } 
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        MDIchild1.MdiParent = Me
        MDIchild1.Show()
        MDIchild2.MdiParent = Me
        MDIchild2.Show()
End Sub