GUI Windows Form C#

/*
Professional Windows GUI Programming Using C#
by Jay Glynn, Csaba Torok, Richard Conway, Wahid Choudhury, 
   Zach Greenvoss, Shripad Kulkarni, Neil Whitlow
Publisher: Peer Information
ISBN: 1861007663
*/
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace ScrollBars
{
    /// 
    /// Summary description for ScrollBars.
    /// 

    public class ScrollBars : System.Windows.Forms.Form
    {
        private System.Windows.Forms.TextBox textBox1;
        private System.Windows.Forms.VScrollBar vScrollBar1;
        /// 
        /// Required designer variable.
        /// 

        int counter=0;
        private System.Windows.Forms.Label label1;
        private System.ComponentModel.Container components = null;
        public ScrollBars()
        {
            //
            // 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.textBox1 = new System.Windows.Forms.TextBox();
            this.vScrollBar1 = new System.Windows.Forms.VScrollBar();
            this.label1 = new System.Windows.Forms.Label();
            this.SuspendLayout();
            // 
            // textBox1
            // 
            this.textBox1.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
            this.textBox1.ForeColor = System.Drawing.Color.Transparent;
            this.textBox1.Location = new System.Drawing.Point(24, 56);
            this.textBox1.Multiline = true;
            this.textBox1.Name = "textBox1";
            this.textBox1.ReadOnly = true;
            this.textBox1.Size = new System.Drawing.Size(144, 32);
            this.textBox1.TabIndex = 4;
            this.textBox1.Text = "";
            this.textBox1.TextAlign = System.Windows.Forms.HorizontalAlignment.Center;
            // 
            // vScrollBar1
            // 
            this.vScrollBar1.Location = new System.Drawing.Point(168, 56);
            this.vScrollBar1.Name = "vScrollBar1";
            this.vScrollBar1.Size = new System.Drawing.Size(16, 32);
            this.vScrollBar1.TabIndex = 7;
            this.vScrollBar1.Scroll += new System.Windows.Forms.ScrollEventHandler(this.vScrollBar1_Scroll);
            // 
            // label1
            // 
            this.label1.Location = new System.Drawing.Point(8, 16);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(192, 16);
            this.label1.TabIndex = 6;
            this.label1.Text = "Numeric Scolling using VScroll Bars";
            // 
            // ScrollBars
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(208, 109);
            this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                          this.label1,
                                                                          this.vScrollBar1,
                                                                          this.textBox1});
            this.Name = "ScrollBars";
            this.Text = "Numeric Scroll";
            this.Load += new System.EventHandler(this.ScrollBars_Load);
            this.ResumeLayout(false);
        }
        #endregion
        /// 
        /// The main entry point for the application.
        /// 

        [STAThread]
        static void Main() 
        {
            Application.Run(new ScrollBars());
        }
        private void textBox1_TextChanged(object sender, System.EventArgs e)
        {
        }
        private void ScrollBars_Load(object sender, System.EventArgs e)
        {
            // Set the maximum range for the scrollbar
            vScrollBar1.Maximum = 100;
            // Set the minimum range for the scrollbar
            vScrollBar1.Minimum = 0 ; 
            // Set the SmallChange factor
            vScrollBar1.SmallChange = 1;    
        }
        private void vScrollBar1_Scroll(object sender, System.Windows.Forms.ScrollEventArgs e)
        {
            // Check if the increment is Small 
         if ( e.Type == ScrollEventType.Last ) 
            counter = 100  ; 
         else
            // Check if the scroll is moved to minimum pos
            if ( e.Type == ScrollEventType.First) 
            counter = 0  ; 
         else
            // Check if the scroll is moved small distance
            if ( e.Type == ScrollEventType.SmallDecrement ) 
            counter -- ; 
         else
            // Check if the scroll is moved small distance
            if ( e.Type == ScrollEventType.SmallIncrement )
         {
            counter++;
            MessageBox.Show("Small increment");
         }
         else
            // Check if the scroll is moved large distance
            if ( e.Type == ScrollEventType.LargeDecrement ) 
            counter-=5;
         else
            // Check if the scroll is moved large distance
            if ( e.Type == ScrollEventType.LargeIncrement )
         {
            MessageBox.Show("Large increment");
            counter+=5;
         }
         else
            // Check if the scroll is moved to the Min position
            if ( e.Type == ScrollEventType.First ) 
            counter = 0 ; 
         else
            // Check if the scroll to the Max position
            if ( e.Type == ScrollEventType.Last) 
            counter = 100  ; 
        Console.WriteLine(e.NewValue+"\n");
        // Check if the scroll is moved large distance
            if ( counter > 100 ) counter = 100 ; 
            if ( counter < 0 ) counter = 0 ;
            textBox1.Text = counter.ToString() ;
        }
    }
}