private void buttonAddStudent_Click(object sender, EventArgs e)
        {
            Decolorare();
            Student student = new Student();

            #region Variables
            string   fname   = textBoxPrenume.Text;
            string   lname   = textBoxNume.Text;
            string   clasa   = comboBoxClasa.Text;
            DateTime bdate   = dateTimePicker1.Value;
            string   phone   = textBoxTelefon.Text;
            string   address = textBoxAdresa.Text;
            string   gender  = "Male";
            if (radioButtonFemale.Checked)
            {
                gender = "Female";
            }
            MemoryStream pic = new MemoryStream();

            int born_year = dateTimePicker1.Value.Year;
            int this_year = DateTime.Now.Year;
            #endregion
            if ((this_year - born_year < 10) || (this_year - born_year > 100))
            {
                MessageBox.Show("Vârsta trebuie să fie între 10 și 100", "Dată de naștere invalidă", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            else if (verif())
            {
                pictureBoxStudentImage.Image.Save(pic, pictureBoxStudentImage.Image.RawFormat);
                if (student.insertStudent(fname, lname, clasa, bdate, phone, gender, address, pic))
                {
                    MessageBox.Show("Student adăugat", "Adaugă student", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
                else
                {
                    MessageBox.Show("Eroare!", "Adaugă student", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }
            else
            {
                MessageBox.Show("Există câmpuri necompletate!", "Adaugă student", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
            }
        }