private void btn_signup_master_Click(object sender, EventArgs e)
{
mng.SignUpMaster(firstname_input.Text, lastname_input.Text, new List <Course>());
//FileStream file = File.Create("Uni");
//BinaryFormatter bf = new BinaryFormatter();
//bf.Serialize(file, Universal.instance);
//file.Close();
ManagerPanel managerpanel = new ManagerPanel(id);
managerpanel.Show();
this.Hide();
}