how to insert a button in a textbox

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

namespace Test.COM
{
    public class TextBox2 : TextBox
    {
        private Button _DeleteButton;
        private const int BUTTON_WIDTH = 16;

        public TextBox2()
        {
            _DeleteButton = new Button();
            _DeleteButton.Text = "X";
            this._DeleteButton.Width = BUTTON_WIDTH;
            _DeleteButton.Dock = DockStyle.Right;
            this.Controls.Add(_DeleteButton);
        }

        public bool DeleteButtonVisible
        {
            get
            {
                return _DeleteButton.Visible;
            }
            set
            {
                _DeleteButton.Visible = value;
            }
        }
    }
}