private void mouseMove(object sender, MouseEventArgs e)
{
if (dragging)
this.Location = new Point(Cursor.Position.X - dragPos.X, Cursor.Position.Y - dragPos.Y);
else
if (Math.Sqrt(Math.Pow(e.X - dragPos.X, 2) + Math.Pow(e.Y - dragPos.Y, 2)) > 10)
dragging = true;
}