Regarding Tabpages and Richtextbox

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;

namespace NotePagePlusPlusTypeForm
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            tabControl1_SelectedIndexChanged(null, null);
        }

        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #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>
        private void InitializeComponent()
        {
            this.tabControl1 = new System.Windows.Forms.TabControl();
            this.tabPage1 = new System.Windows.Forms.TabPage();
            this.tabControl1.SuspendLayout();
            this.SuspendLayout();
            // 
            // tabControl1
            // 
            this.tabControl1.Controls.Add(this.tabPage1);
            this.tabControl1.Dock = System.Windows.Forms.DockStyle.Fill;
            this.tabControl1.Location = new System.Drawing.Point(0, 0);
            this.tabControl1.Name = "tabControl1";
            this.tabControl1.SelectedIndex = 0;
            this.tabControl1.Size = new System.Drawing.Size(284, 262);
            this.tabControl1.TabIndex = 0;
            this.tabControl1.SelectedIndexChanged += new System.EventHandler(this.tabControl1_SelectedIndexChanged);
            // 
            // tabPage1
            // 
            this.tabPage1.Location = new System.Drawing.Point(4, 22);
            this.tabPage1.Name = "tabPage1";
            this.tabPage1.Padding = new System.Windows.Forms.Padding(3);
            this.tabPage1.Size = new System.Drawing.Size(276, 236);
            this.tabPage1.TabIndex = 0;
            this.tabPage1.Text = "+";
            this.tabPage1.UseVisualStyleBackColor = true;
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(284, 262);
            this.Controls.Add(this.tabControl1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.Load += new System.EventHandler(this.Form1_Load);
            this.tabControl1.ResumeLayout(false);
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.TabControl tabControl1;
        private System.Windows.Forms.TabPage tabPage1;

        private void tabControl1_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (tabControl1.SelectedIndex == tabControl1.TabCount - 1)
            {
                // we selected the last [+] tab let's create a new page
                int pageNo=tabControl1.TabPages.Count;
                var newTabPage = new TabPage("Page " + pageNo);
                newTabPage.Controls.Add(new RichTextBox() { Dock = DockStyle.Fill, Text = "This is RichTextControl " + pageNo });
                tabControl1.TabPages.Insert(pageNo - 1, newTabPage);
                tabControl1.SelectedIndex = pageNo - 1;
            }
        }
    }
}