private void MainGotoGameBtn_Click(object sender, EventArgs e)
 {
     if (gf == null)
     {
         gf = new GameMenuForm();
         gf.FormClosed += Gf_FormClosed;
         gf.Show();
         this.Hide();
     }
     else
     {
         gf.Activate();
     }
 }
 private void Gf_FormClosed(object sender, FormClosedEventArgs e)
 {
     gf = null;
     //throw new NotImplementedException();
 }