using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

public class frmScribble : System.Windows.Forms.Form
{
 private System.ComponentModel.Container components = null;
 private bool mouseDown = false;
 private Point lastPoint = Point.Empty;
 private string color = "black";
 private Graphics g;
 private Pen p;

 public frmScribble()
 {
  g = CreateGraphics();
  p = new Pen(Color.FromName(color));

 }
 protected override void OnMouseDown(MouseEventArgs e)
 {
  mouseDown = true;
  if (e.Button == MouseButtons.Right)
  {
   ContextMenu m = new ContextMenu();
   m.MenuItems.Add(0, new MenuItem("black", new EventHandler(RightMouseButton_Click)));
   m.MenuItems.Add(1, new MenuItem("white", new EventHandler(RightMouseButton_Click)));
   m.MenuItems.Add(2, new MenuItem("red", new EventHandler(RightMouseButton_Click)));
   m.MenuItems.Add(3, new MenuItem("green", new EventHandler(RightMouseButton_Click)));
   m.MenuItems.Add(4, new MenuItem("blue", new EventHandler(RightMouseButton_Click)));
   m.Show(this, new Point(e.X, e.Y));
  }
 }

 protected void RightMouseButton_Click(object sender, EventArgs e)
 {
  color = ((MenuItem)sender).Text;
  p = new Pen(Color.FromName(color));
 }

 protected override void OnMouseUp(MouseEventArgs e)
 {
  mouseDown = false;
 }

 protected override void OnMouseMove(MouseEventArgs e)
 {
  if (lastPoint.Equals(Point.Empty)) lastPoint = new Point(e.X, e.Y);
  if (mouseDown)
  {
   Point pMousePos = new Point(e.X, e.Y);
   g.DrawLine(p, pMousePos, lastPoint);
  }
  lastPoint = new Point(e.X, e.Y);
 }

 [STAThread]
 static void Main()
 {
  Application.Run(new frmScribble());
 }
}