Composite control with design-time support

//MY COMPLAINT IS THAT THE TEXT BOXES IN THIS SAMPLE (gotton off of MSDN) DO NOT SHOW-UP WHEN I DROP THE CONTROL ONTO A WEB PAGE.  I WANT THEM TO BE VISIBLE AT DESIGN-TIME AND WHEN I CLICK ON THEM I WANT TO SEE THEIR PROPERTIES IN THE PROPERTIES WINDOW.
 
 
using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
 
namespace WebControlLibrary1 
{
      
      public class Composite : Control, INamingContainer 
      {
            private int number = 100;
            private Label label;
            
            public int Number
            {
                  get
                  {
                        return number;
                  }
                  set
                  {
                        number = value;
                  }
            }
            
            private int Sum
            {
                  get 
                  {
                        EnsureChildControls();
                        return Int32.Parse(((TextBox)Controls[1]).Text) + 
                              Int32.Parse(((TextBox)Controls[4]).Text);
                  }
                  
            }
 
            public string Text
            {
                  get
                  {
                    EnsureChildControls();
                        return label.Text;
                  }
                  set
                  {
                    EnsureChildControls();
                        label.Text = value;
                  }
            }
            
            
            public event CheckEventHandler Check;
            
            protected virtual void OnCheck(CheckEventArgs ce)
            {
                  if (Check != null)
                  {
                        Check(this,ce);
                  }
            }
            
            protected override void CreateChildControls() 
            {
                  
                  Controls.Add(new LiteralControl("<h3>Enter a number : "));
                  
                  TextBox box1 = new TextBox();
                  box1.Text = "0";
                  Controls.Add(box1);
                  
                  Controls.Add(new LiteralControl("</h3>"));
                  
                  Controls.Add(new LiteralControl("<h3>Enter another number : "));
                  
                  TextBox box2 = new TextBox();
                  box2.Text = "0";
                  Controls.Add(box2);
                  
                  Controls.Add(new LiteralControl("</h3>"));
                  
                  Button button1 = new Button();
                  button1.Text = "Submit";
                  Controls.Add(new LiteralControl("<br>"));
                  Controls.Add(button1);
                  button1.Click += new EventHandler(this.ButtonClicked);
                  
                  Controls.Add(new LiteralControl("<br><br>"));
                  label = new Label();
                  label.Height = 50;
                  label.Width = 500;
                  label.Text = "Click the button to see if you won.";
                  Controls.Add(label);
                  
            }
            
            protected override void OnPreRender(EventArgs e)
            {
                  ((TextBox)Controls[1]).Text = "0";
                  ((TextBox)Controls[4]).Text = "0";
            }
            
            private void ButtonClicked(Object sender, EventArgs e)
            {
                  OnCheck(new CheckEventArgs(Sum - Number));
            }
      }
}

                                  

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