public FormSecretary_AddOrRemoveLecture(int _id, string _password)
        {
            InitializeComponent();

            string        department;
            List <string> coursesProperties = new List <string>();
            List <int>    coursesID         = new List <int>();
            List <int>    lecturesID        = new List <int>();

            id                = _id;
            password          = _password;
            department        = SQLFunctions.getUsersDepartment(id);
            coursesProperties = SQLFunctions.findCoursePropertiesByDepartment(department);
            for (int i = 1; i < coursesProperties.Count; i += 9)
            {
                coursesID.Add(Convert.ToInt32(coursesProperties[i]));
            }

            for (int i = 0; i < coursesID.Count; i++)
            {
                lecturesID = SQLFunctions.findLecturesIDsForCourse(coursesID[i]);
                for (int j = 0; j < lecturesID.Count; j++)
                {
                    lectureIDS.Add(lecturesID[j]);
                    comboBox_Lectures.Items.Add(SQLFunctions.covertLectureIDtoLectureName(lecturesID[j]) + " " + lecturesID[j]);
                }
            }

            comboBox_Lectures.Items.Add("All");
            this.AcceptButton                = button_accept;
            textBox_StartTime.MaxLength      = 2;
            textBox_EndTime.MaxLength        = 2;
            textBox_day.MaxLength            = 2;
            textBox_month.MaxLength          = 2;
            textBox_year.MaxLength           = 2;
            comboBox_AddRemove.DropDownStyle = ComboBoxStyle.DropDownList;
            comboBox_Lectures.DropDownStyle  = ComboBoxStyle.DropDownList;
        }
        private void button_accept_Click(object sender, EventArgs e)
        {
            int        lectureID;
            List <int> studentIDs = new List <int>();
            string     dayForConstraints;
            string     month;

            if (comboBox_AddRemove.SelectedIndex == 0)
            {
                if (verify_details() == true)
                {
                    SQLFunctions.addChange(textBox_title.Text, textBox_description.Text, Convert.ToInt32(textBox_StartTime.Text), Convert.ToInt32(textBox_EndTime.Text), Convert.ToInt32(textBox_day.Text), Convert.ToInt32(textBox_month.Text), Convert.ToInt32(comboBox_year.Text), lectureIDS[comboBox_Lectures.SelectedIndex]);

                    MessageBox.Show("Lesson was successfuly added");
                }
            }
            else if (comboBox_AddRemove.SelectedIndex == 1)
            {
                lectureID = lectureIDS[comboBox_Lectures.SelectedIndex];
                SQLFunctions.addChange(textBox_title.Text, textBox_description.Text, Convert.ToInt32(label_startTime.Text), Convert.ToInt32(label_endTime.Text), Convert.ToInt32(comboBox_day.Text), Convert.ToInt32(comboBox_month.Text), Convert.ToInt32(comboBox_year.Text), lectureID);

                DateTime day = new DateTime(Convert.ToInt32(comboBox_year.Items[comboBox_year.SelectedIndex]), Convert.ToInt32(comboBox_month.Items[comboBox_month.SelectedIndex]), Convert.ToInt32(comboBox_day.Items[comboBox_day.SelectedIndex]));
                month = comboBox_month.Items[comboBox_month.SelectedIndex].ToString();

                if ((Convert.ToInt32(comboBox_day.Items[comboBox_day.SelectedIndex])) < 10)
                {
                    dayForConstraints = "0" + comboBox_day.Items[comboBox_day.SelectedIndex].ToString();
                }
                else
                {
                    dayForConstraints = comboBox_day.Items[comboBox_day.SelectedIndex].ToString();
                }
                if ((Convert.ToInt32(comboBox_month.Items[comboBox_day.SelectedIndex])) < 10)
                {
                    month = "0" + month;
                }
                if (day > (new DateTime(Convert.ToInt32(day.Year), 03, 05)) && day < (new DateTime(Convert.ToInt32(day.Year), 6, 15)))
                {
                    SQLFunctions.addConstraint(SQLFunctions.getLecturerIDByLecturerName(SQLFunctions.findLecturerNameByLectureID(lectureID)), day.DayOfWeek.ToString(), (label_startTime.Text + ":00").ToString(), (label_endTime.Text + ":00").ToString(), textBox_description.Text.ToString(), SQLFunctions.findLecturerNameByLectureID(lectureID), (dayForConstraints + "/" + month + "/" + comboBox_year.Items[comboBox_year.SelectedIndex].ToString()), "B", (SQLFunctions.covertLectureIDtoLectureName(lectureIDS[comboBox_Lectures.SelectedIndex])).ToString());
                }
                else if (day > new DateTime(Convert.ToInt32(day.Year), 10, 30) && day < new DateTime(Convert.ToInt32(day.Year), 2, 4))
                {
                    SQLFunctions.addConstraint(SQLFunctions.getLecturerIDByLecturerName(SQLFunctions.findLecturerNameByLectureID(lectureID)), day.DayOfWeek.ToString(), (label_startTime.Text + ":00").ToString(), (label_endTime.Text + ":00").ToString(), textBox_description.Text.ToString(), SQLFunctions.findLecturerNameByLectureID(lectureID), (dayForConstraints + "/" + month + "/" + comboBox_year.Items[comboBox_year.SelectedIndex].ToString()), "A", (SQLFunctions.covertLectureIDtoLectureName(lectureIDS[comboBox_Lectures.SelectedIndex])).ToString());
                }
                MessageBox.Show("Lesson was successfuly removed");
            }
            else if (comboBox_AddRemove.SelectedIndex == 2)
            {
                if (verify_details() == true)
                {
                    DateTime day = new DateTime(Convert.ToInt32(comboBox_year.Items[comboBox_year.SelectedIndex]), Convert.ToInt32(textBox_month.Text), Convert.ToInt32(textBox_day.Text));
                    month             = textBox_month.Text.ToString();
                    dayForConstraints = textBox_day.Text.ToString();
                    if (Convert.ToInt32(textBox_day.Text) < 10)
                    {
                        if (!textBox_day.Text.Contains('0'))
                        {
                            dayForConstraints = "0" + textBox_day.Text;
                        }
                    }

                    if (Convert.ToInt32(textBox_month.Text) < 10)
                    {
                        if (!textBox_month.Text.Contains('0'))
                        {
                            month = "0" + textBox_month.Text;
                        }
                    }
                    SQLFunctions.addChange(textBox_title.Text, textBox_description.Text, Convert.ToInt32(textBox_StartTime.Text), Convert.ToInt32(textBox_EndTime.Text), Convert.ToInt32(textBox_day.Text), Convert.ToInt32(textBox_month.Text), Convert.ToInt32(comboBox_year.Text), 0);
                    if (day > new DateTime(Convert.ToInt32(day.Year), 3, 5) && day < new DateTime(Convert.ToInt32(day.Year), 6, 15))
                    {
                        SQLFunctions.addConstraint("0", day.DayOfWeek.ToString(), (textBox_StartTime.Text + ":00").ToString(), (textBox_EndTime.Text + ":00").ToString(), textBox_description.Text.ToString(), "", (dayForConstraints + "/" + month + "/" + comboBox_year.Items[comboBox_year.SelectedIndex].ToString()), "B", "General");
                    }
                    else if (day > new DateTime(Convert.ToInt32(day.Year), 10, 30) && day < new DateTime(Convert.ToInt32(day.Year), 2, 4))
                    {
                        SQLFunctions.addConstraint("0", day.DayOfWeek.ToString(), (textBox_StartTime.Text + ":00").ToString(), (textBox_EndTime.Text + ":00").ToString(), textBox_description.Text.ToString(), "", (dayForConstraints + "/" + month + "/" + comboBox_year.Items[comboBox_year.SelectedIndex].ToString()), "A", "General");
                    }
                    MessageBox.Show("Event was successfuly Added");
                }
            }
            foreach (Control c in this.Controls)
            {
                if ((c.GetType() == typeof(TextBox)) || (c.GetType() == typeof(ComboBox)))
                {
                    c.Text = "";
                }
            }
        }