//postfix
private void button1_Click(object sender, EventArgs e)
{
postfix = new FormPostfix();
postfix.Show();
this.Visible = false;
this.Close();
}
private void button1_Click(object sender, EventArgs e) //postfix
{
postfix = new FormPostfix();
postfix.Show();
this.Visible = false;
this.Close();
}