User resizable panel

using System;
using System.Drawing;
using System.Windows.Forms;

public class SizeablePanel : Panel {
private const int cGripSize = 20;
private bool mDragging;
private Point mDragPos;

public SizeablePanel() {
this.DoubleBuffered = true;
this.SetStyle(ControlStyles.ResizeRedraw, true);
this.BackColor = Color.White;
}

protected override void OnPaint(PaintEventArgs e) {
ControlPaint.DrawSizeGrip(e.Graphics, this.BackColor,
new Rectangle(this.ClientSize.Width - cGripSize, this.ClientSize.Height - cGripSize, cGripSize, cGripSize));
base.OnPaint(e);
}

private bool IsOnGrip(Point pos) {
return pos.X >= this.ClientSize.Width - cGripSize &&
pos.Y >= this.ClientSize.Height - cGripSize;
}

protected override void OnMouseDown(MouseEventArgs e) {
mDragging = IsOnGrip(e.Location);
mDragPos = e.Location;
base.OnMouseDown(e);
}

protected override void OnMouseUp(MouseEventArgs e) {
mDragging = false;
base.OnMouseUp(e);
}

protected override void OnMouseMove(MouseEventArgs e) {
if (mDragging) {
this.Size = new Size(this.Width + e.X - mDragPos.X,
this.Height + e.Y - mDragPos.Y);
mDragPos = e.Location;
}
else if (IsOnGrip(e.Location)) this.Cursor = Cursors.SizeNWSE;
else this.Cursor = Cursors.Default;
base.OnMouseMove(e);
}
}