Inheritance: Telerik.WinControls.UI.RadForm
        private void addAlternativeClassroomsButton_Click(object sender, EventArgs e)
        {
            List<ChooseItemsParameters> classrooms = new List<ChooseItemsParameters>();
            List<ChooseItemsParameters> alreadySelectedClassrooms = new List<ChooseItemsParameters>();
            foreach (var classroom in mDBManager.Classrooms)
            {
                if (long.Parse(dropDownListWantedRoom.SelectedValue.ToString()) != classroom.ID)
                {
                    classrooms.Add(new ChooseItemsParameters(classroom.Name, classroom.ShortName, classroom.ID));
                }
            }

            if (mFormState == FormState.AddingNew)
            {
                chooseAlternativeClassroomsForm = new ChooseItemsForm(ChooseItems.Mode.MultipleItems, "Избери алтернативни стаи за този урок", classrooms);
            }

            if(mFormState == FormState.Editing){
                foreach(var room in mLesson.AlternativeClassrooms){
                    alreadySelectedClassrooms.Add(new ChooseItemsParameters(room.Name, room.ShortName, room.ID));
                }

                chooseAlternativeClassroomsForm = new ChooseItemsForm(ChooseItems.Mode.MultipleItems, "Редактирай алтернативните стаи за този урок", classrooms, alreadySelectedClassrooms);
            }

            chooseAlternativeClassroomsForm.OnReadyButtonClicked += chooseAlternativeClassroomsForm_OnReadyButtonClicked;
            chooseAlternativeClassroomsForm.Show();
        }
        private void chooseSubjectsToBeTaughtInThisRoomButton_Click(object sender, EventArgs e)
        {
            List<ChooseItemsParameters> subjects = new List<ChooseItemsParameters>();

            foreach (var s in mDBManager.Subjects)
            {
                subjects.Add(new ChooseItemsParameters(s.Name, s.ShortName, s.ID));
            }

            Console.WriteLine("Count of the subjects: {0}", subjects.Count);

            List<ChooseItemsParameters> alreadySpecialisatedSubjects = new List<ChooseItemsParameters>();
            try
            {
                foreach (var sID in specialisatedSubjectsIDs)
                {
                    foreach (var subject in mDBManager.Subjects)
                    {
                        if (sID == subject.ID)
                        {
                            alreadySpecialisatedSubjects.Add(new ChooseItemsParameters(subject.Name, subject.ShortName, subject.ID));
                        }
                    }
                }
            }
            catch { }
            try
            {
                chooseSubjectsToBeTaughtForm.gridviewItems.Rows.Clear();
            }
            catch { }
            chooseSubjectsToBeTaughtForm = new ChooseItemsForm(ChooseItems.Mode.MultipleItems, "Избери предмети, които да се преподават в тази стая", subjects, alreadySpecialisatedSubjects);
            chooseSubjectsToBeTaughtForm.OnReadyButtonClicked += chooseSubjectsToBeTaught_OnReadyButtonClicked;
            chooseSubjectsToBeTaughtForm.Show();
        }
        private void chooseHeadclassOfThisClassroom_Click(object sender, EventArgs e)
        {
            if (mFormState == FormState.AddingNew)
            {
                List<ChooseItemsParameters> classes = new List<ChooseItemsParameters>();
                foreach (var s in mDBManager.Classes)
                {
                    classes.Add(new ChooseItemsParameters(s.Name, s.ShortName, s.ID));
                }
                chooseHeadclassOfThisClassroomForm = new ChooseItemsForm(ChooseItems.Mode.SingleItem, "Избери клас, на който тази стая да бъде класна стая", classes);
            }
            if (mFormState == FormState.Editing)
            {
                List<ChooseItemsParameters> classes = new List<ChooseItemsParameters>();
                foreach (var s in mDBManager.Classes)
                {
                    classes.Add(new ChooseItemsParameters(s.Name, s.ShortName, s.ID));
                }

                List<ChooseItemsParameters> alreadyChoosedClass = new List<ChooseItemsParameters>();
                Class choosedClass = mDBManager.Classes[0];
                foreach(Class c in mDBManager.Classes){
                    if(c.ID == mHomeClassID){
                        choosedClass = c;
                        break;
                    }
                }
                alreadyChoosedClass.Add(new ChooseItemsParameters(choosedClass.Name, choosedClass.Name, choosedClass.ID));
                chooseHeadclassOfThisClassroomForm = new ChooseItemsForm(ChooseItems.Mode.SingleItem, "Избери клас, на който тази стая да бъде класна стая", classes, alreadyChoosedClass);
            }
            chooseHeadclassOfThisClassroomForm.OnReadyButtonClicked += chooseHeadclassOfThisClassroom_OnReadyButtonClicked;
            chooseHeadclassOfThisClassroomForm.Show();
        }