private void Change_Click(object sender, EventArgs e)
{
   refout temp = new refout();
   int x = System.Convert.ToInt32(textBox1.Text, 10);
   int y = System.Convert.ToInt32(textBox2.Text, 10);
   temp.Swap(ref x, ref y);
   textBox1.Text = x.ToString();
   textBox2.Text = y.ToString();
}
