private void frmDrag_Paint(object sender, PaintEventArgs e) {
  //Draws a border to make the Form stand out
  //Just done for appearance, not necessary

  Pen p = new Pen(Color.Gray, 3);
  e.Graphics.DrawRectangle(p, 0, 0, this.Width - 1, this.Height - 1);
  p.Dispose();
}

Point lastClick; //Holds where the Form was clicked

private void frmDrag_MouseDown(object sender, MouseEventArgs e) {
  lastClick = new Point(e.X, e.Y); //We'll need this for when the Form starts to move
}

private void frmDrag_MouseMove(object sender, MouseEventArgs e) {
  //Point newLocation = new Point(e.X - lastE.X, e.Y - lastE.Y);
  if (e.Button == MouseButtons.Left) //Only when mouse is clicked
  {
    //Move the Form the same difference the mouse cursor moved;
    this.Left += e.X - lastClick.X;
    this.Top += e.Y - lastClick.Y;
  }
}

//If the user clicks on the label we want the same kind of behavior
//so we just call the Forms corresponding methods
private void label1_MouseDown(object sender, MouseEventArgs e) {
  frmDrag_MouseDown(sender, e);
}

private void label1_MouseMove(object sender, MouseEventArgs e) {
  frmDrag_MouseMove(sender, e);
}