how to crop image in .net

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using Swash.Objects;
using Swash.BusinessLayer;
using System.Data.SqlClient;

namespace POS
{
    public partial class frmCropImage : Form
    {
       frmCustomer cust;
       public byte[] CropImag;  
       int cropX;
       int cropY;
       int cropWidth;
       int cropHeight;
       int oCropX;
       int oCropY;
       public Pen cropPen;
       public Bitmap _img;
       public DashStyle cropDashStyle = DashStyle.DashDot;
        public frmCropImage( )
        {
            InitializeComponent();     
        }

        private void frmCropImage_Load(object sender, EventArgs e)
        {

            //frmCustomer obj=new frmCustomer();
            string Path = frmCustomer.ImagPath;
            pbimage.Image = new Bitmap(Path);

        }

        private void btnCrop_Click(object sender, EventArgs e)
        {
            Cursor = Cursors.Default;

            try
            {
                if (cropWidth < 1)
                {
                    return;
                }
                Rectangle rect = new Rectangle(cropX, cropY, cropWidth, cropHeight);
                //First we define a rectangle with the help of already calculated points
                Bitmap OriginalImage = new Bitmap(pbimage.Image, pbimage.Width, pbimage.Height);
                //Original image
                _img = new Bitmap(cropWidth, cropHeight);
                // for cropinf image
                Graphics g = Graphics.FromImage(_img);
                // create graphics
                g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                g.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
                g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
                //set image attributes
                g.DrawImage(OriginalImage, 0, 0, rect, GraphicsUnit.Pixel);

                pbimage.Image = _img;
                pbimage.Width = _img.Width;
                pbimage.Height = _img.Height;
             //   PictureBoxLocation();
                btnCrop.Enabled = false;
             
                //obj.PictureBoxCustomer.Image = null;
                //obj.PictureBoxCustomer.Image = _img;
                //Image img = _img;       
                //using (MemoryStream ms = new MemoryStream())
                //{
                //    img.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
                //    CropImag = ms.ToArray();
                //}            
               
            }
           
            catch (Exception ex)
            {
            }
        }

        //private void PictureBoxLocation()
        //{
        //    int _x = 0;
        //    int _y = 0;
        //    if (SplitContainer1.Panel1.Width > PictureBox1.Width)
        //    {
        //        _x = (SplitContainer1.Panel1.Width - PictureBox1.Width) / 2;
        //    }
        //    if (SplitContainer1.Panel1.Height > PictureBox1.Height)
        //    {
        //        _y = (SplitContainer1.Panel1.Height - PictureBox1.Height) / 2;
        //    }
        //    PictureBox1.Location = new Point(_x, _y);
        //}

        private void frmCropImage_MouseDown(object sender, MouseEventArgs e)
        {
            //if (e.Button == System.Windows.Forms.MouseButtons.Left)
            //{
            //    Cursor = Cursors.Cross;
            //    cropX = e.X;
            //    cropY = e.Y;

            //    cropPen = new Pen(Color.Black, 1);
            //    cropPen.DashStyle = DashStyle.DashDotDot;


            //}
            //pbimage.Refresh();
        }

        private void frmCropImage_MouseMove(object sender, MouseEventArgs e)
        {
            //if (pbimage.Image == null)
            //    return;


            //if (e.Button == System.Windows.Forms.MouseButtons.Left)
            //{
            //    pbimage.Refresh();
            //    cropWidth = e.X - cropX;
            //    cropHeight = e.Y - cropY;
            //    pbimage.CreateGraphics().DrawRectangle(cropPen, cropX, cropY, cropWidth, cropHeight);
            //}
        }

        private void pbimage_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == System.Windows.Forms.MouseButtons.Left)
            {
                Cursor = Cursors.Cross;
                cropX = e.X;
                cropY = e.Y;
                cropPen = new Pen(Color.Black, 1);
                cropPen.DashStyle = DashStyle.DashDotDot;
            }
            pbimage.Refresh();
        }

        private void pbimage_MouseMove(object sender, MouseEventArgs e)
        {
            if (pbimage.Image == null)
                return;
            if (e.Button == System.Windows.Forms.MouseButtons.Left)
            {
                pbimage.Refresh();
                cropWidth = e.X - cropX;
                cropHeight = e.Y - cropY;
                pbimage.CreateGraphics().DrawRectangle(cropPen, cropX, cropY, cropWidth, cropHeight);
            }
        }

        private void pbimage_MouseUp(object sender, MouseEventArgs e)
        {
            Cursor = Cursors.Default;
        }

        private void btnClose_Click(object sender, EventArgs e)
        {
            this.Close();
        }
    }
}