private void ButtonTrainee_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                if (this.ComboBoxTraineeBy.SelectedItem == this.AllTrainees)
                {
                    LinqToALL lg = new LinqToALL();
                    lg.Source = bl.traineesList();

                    this.showListsTrainee.Content = lg;
                    return;
                }

                if (this.ComboBoxTraineeBy.SelectedItem == this.schoolName)
                {
                    LinqGroupingUserControl1 lg = new LinqGroupingUserControl1();
                    lg.Source = bl.groupTraineeByDrivingSchool();

                    this.showListsTrainee.Content = lg;
                    return;
                }

                if (this.ComboBoxTraineeBy.SelectedItem == this.driningTeacher)
                {
                    LinqGroupingUserControl1 lg = new LinqGroupingUserControl1();
                    lg.Source = bl.groupTraineeByNameOfTeacher();

                    this.showListsTrainee.Content = lg;
                    return;
                }

                if (this.ComboBoxTraineeBy.SelectedItem == this.numdOfTestsDoing)
                {
                    LinqGroupingUserControl1 lg = new LinqGroupingUserControl1();
                    lg.Source = bl.groupTraineeByNumOfTests();

                    this.showListsTrainee.Content = lg;
                    return;
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        private void ButtonTest_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                if (this.ComboBoxTestBy.SelectedItem == this.AllTests)
                {
                    LinqToALL lg = new LinqToALL();
                    lg.Source = bl.testsList();

                    this.showListsTest.Content = lg;
                    return;
                }
                if (this.ComboBoxTestBy.SelectedItem == this.successOrNot)
                {
                    LinqGroupingUserControl1 lg = new LinqGroupingUserControl1();
                    lg.Source = bl.groupTestBySuccessOrNot();

                    this.showListsTest.Content = lg;
                    return;
                }

                if (this.ComboBoxTestBy.SelectedItem == this.doingOrNot)
                {
                    LinqGroupingUserControl1 lg = new LinqGroupingUserControl1();
                    lg.Source = bl.groupTestByDone();

                    this.showListsTest.Content = lg;
                    return;
                }

                if (this.ComboBoxTestBy.SelectedItem == this.IdOfTest)
                {
                    LinqGroupingUserControl1 lg = new LinqGroupingUserControl1();
                    lg.Source = bl.groupTestByIdTester();

                    this.showListsTest.Content = lg;
                    return;
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        private void ButtonTester_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                if (this.ComboBoxTesterBy.SelectedItem == this.AllTesters)
                {
                    LinqToALL lg = new LinqToALL();
                    lg.Source = bl.testersList();

                    this.showListsTester.Content = lg;
                    return;
                }

                if (this.ComboBoxTesterBy.SelectedItem == this.specializationOfTesters)
                {
                    LinqGroupingUserControl1 lg = new LinqGroupingUserControl1();
                    lg.Source = bl.groupTesterByCarType();


                    this.showListsTester.Content = lg;
                    return;
                }

                if (this.ComboBoxTesterBy.SelectedItem == this.AgeOfTesters)
                {
                    LinqGroupingUserControl1 lg = new LinqGroupingUserControl1();
                    lg.Source = bl.groupTesterByAge();

                    this.showListsTester.Content = lg;
                    return;
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }