GUI Windows Form C#

/*
User Interfaces in C#: Windows Forms and Custom Controls
by Matthew MacDonald
Publisher: Apress
ISBN: 1590590457
*/
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace ImpossibleAPI
{
    
    public class Global
    {
        public static Form1 Main1 = new Form1();
        public static Form1 Main2 = new Form1();
        public static Form2 Child = new Form2();                                
                                                                                
        [STAThread]
        public static void Main() 
        {
            Main1.Text = "Parent 2";
            Main2.Text = "Parent 1";
            Main1.Show();
            Main2.Show();
            
            Child.MdiParent = Main2;
            Child.Show();
            System.Windows.Forms.Application.Run();
        }
        
    }
    /// 
    /// Summary description for Form2.
    /// 

    public class Form2 : System.Windows.Forms.Form
    {
        internal System.Windows.Forms.Button Button3;
        internal System.Windows.Forms.Button Button2;
        internal System.Windows.Forms.Button Button1;
        /// 
        /// Required designer variable.
        /// 

        private System.ComponentModel.Container components = null;
        public Form2()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();
            //
            // TODO: Add any constructor code after InitializeComponent call
            //
        }
        /// 
        /// Clean up any resources being used.
        /// 

        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if(components != null)
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }
        #region Windows Form Designer generated code
        /// 
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// 

        private void InitializeComponent()
        {
            this.Button3 = new System.Windows.Forms.Button();
            this.Button2 = new System.Windows.Forms.Button();
            this.Button1 = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // Button3
            // 
            this.Button3.Location = new System.Drawing.Point(124, 60);
            this.Button3.Name = "Button3";
            this.Button3.Size = new System.Drawing.Size(88, 32);
            this.Button3.TabIndex = 5;
            this.Button3.Text = "Become Child of Parent2";
            this.Button3.Click += new System.EventHandler(this.Button3_Click);
            // 
            // Button2
            // 
            this.Button2.Location = new System.Drawing.Point(16, 60);
            this.Button2.Name = "Button2";
            this.Button2.Size = new System.Drawing.Size(88, 32);
            this.Button2.TabIndex = 4;
            this.Button2.Text = "Become Child of Parent1";
            this.Button2.Click += new System.EventHandler(this.Button2_Click);
            // 
            // Button1
            // 
            this.Button1.Location = new System.Drawing.Point(16, 16);
            this.Button1.Name = "Button1";
            this.Button1.Size = new System.Drawing.Size(88, 32);
            this.Button1.TabIndex = 3;
            this.Button1.Text = "Become Parent";
            this.Button1.Click += new System.EventHandler(this.Button1_Click);
            // 
            // Form2
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 14);
            this.ClientSize = new System.Drawing.Size(292, 150);
            this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                          this.Button3,
                                                                          this.Button2,
                                                                          this.Button1});
            this.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
            this.Name = "Form2";
            this.Text = "Form2";
            this.ResumeLayout(false);
        }
        #endregion
        private void Button1_Click(object sender, System.EventArgs e)
        {
            this.Hide();
            this.MdiParent = null;
            this.IsMdiContainer = true;
            this.Show();
        }
        private void Button2_Click(object sender, System.EventArgs e)
        {
            this.Hide();
            this.IsMdiContainer = false;
            this.MdiParent = Global.Main2;
            this.Show();
        }
        private void Button3_Click(object sender, System.EventArgs e)
        {
            this.Hide();
            this.IsMdiContainer = false;
            this.MdiParent = Global.Main1;
            this.Show();
        }
    }
    /// 
    /// Summary description for Form1.
    /// 

    public class Form1 : System.Windows.Forms.Form
    {
        /// 
        /// Required designer variable.
        /// 

        private System.ComponentModel.Container components = null;
        public Form1()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();
            //
            // TODO: Add any constructor code after InitializeComponent call
            //
        }
        /// 
        /// Clean up any resources being used.
        /// 

        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if (components != null) 
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }
        #region Windows Form Designer generated code
        /// 
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// 

        private void InitializeComponent()
        {
            // 
            // Form1
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(464, 370);
            this.IsMdiContainer = true;
            this.Name = "Form1";
            this.Text = "Form1";
            this.Closing += new System.ComponentModel.CancelEventHandler(this.Form1_Closing);
            this.Load += new System.EventHandler(this.Form1_Load);
        }
        #endregion
        private void Form1_Load(object sender, System.EventArgs e)
        {
        
        }
        private void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
        {
            Application.Exit();
        }
        /// 
        /// The main entry point for the application.
        /// 

    }
}