private void button1_Click(object sender, EventArgs e)
        {
            TableStudent s = new TableStudent();

            s.Email = textBox3.Text;
            s.Name  = this.textBox2.Text;
            s.Id    = Convert.ToInt32(textBox1.Text);

            crmEntities crmEntities = new crmEntities();

            crmEntities.TableStudents.Add(s);
            crmEntities.SaveChanges();

            if (crmEntities.TableStudents.Any(n => n.Id == s.Id))
            {
                MessageBox.Show(s.Id + "Added!");
            }
        }