Guess My Drawing!

using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Net;
using System.Data;

namespace WindowsFormsApplication1
{
    public class MyPanel : Panel
    {
        public static Pen p;
        public string pen_color = "blue";
        private bool mouse_down = false;
        public static Point last_point = Point.Empty;
        private Graphics g;
        ArrayList pointss;
        public static UdpClient client;

        public MyPanel()
        {
            g = this.CreateGraphics();
            p = new Pen(Color.FromName(pen_color));
            g.Clip.MakeInfinite();
            pointss = new ArrayList();
        }
        protected override void OnMouseDown(MouseEventArgs e)
        {
            mouse_down = true;
        }
        protected override void OnMouseUp(MouseEventArgs e)
        {
            mouse_down = false;
            if (Form1.isDrawer)
            {
                string msg = "draw";
                for (int i = 0; i < pointss.Count; i++)
                {
                    Point poi = (Point)pointss[i];
                    msg += ("x" + poi.X + "y" + poi.Y);
                }
                msg += "x";
                pointss.Clear();
                byte[] data = Encoding.ASCII.GetBytes(msg);
                if (client != null)
                    client.Send(data, data.Length);
            }
        }
        protected override void OnMouseMove(MouseEventArgs e)
        {
            if (Form1.isDrawer)
            {
                if (last_point.Equals(Point.Empty))
                    last_point = new Point(e.X, e.Y);
                if (mouse_down)
                {

                    IntPtr hwnd = this.Handle;

                    using (Graphics graphics = Graphics.FromHwnd(hwnd))
                    {
                        Point pMousePos = new Point(e.X, e.Y);
                        graphics.DrawLine(p, pMousePos, last_point);
                        Console.WriteLine(pMousePos + "  last  " + last_point);
                        pointss.Add(pMousePos);
                    }
                }
                last_point = new Point(e.X, e.Y);
            }
        }
    }
    
}