[C#] Move a Borderless Form

Code:

private bool _dragging = false;
private Point _offset;
private Point _start_point=new Point(0,0);


private void MouseDown(object sender, MouseEventArgs e)
{
   _dragging = true;  // _dragging is your variable flag
   _start_point = new Point(e.X, e.Y);
}

private void MouseUp(object sender, MouseEventArgs e)
{
   _dragging = false; 
}

private void MouseMove(object sender, MouseEventArgs e)
{
  if(_dragging)
  {
     Point p = PointToScreen(e.Location);
     Location = new Point(p.X - this._start_point.X,p.Y - this._start_point.Y);     
  }
}