public void valueChanged(ListSelectionEvent event) {
		if (!event.getValueIsAdjusting()) {
			if (event.getSource() == userTable.getSelectionModel()) {
				clearPreferenceCompareTable();
	 			User selectedUser = userTable.getSelectedUser();
				if (selectedUser != null) {
					long userId = selectedUser.getId();
					itemTable.clearPreference();
					List<Preference> preferences = mahoutDemoUI.getDataModelBuilder().getUserPreferences(userId);
					for (Preference preference : preferences) {
						itemTable.setPreference(preference.getItemId(), preference.getPreference());
					}
					
					itemTable.updateUI();
				}
	
				similarUserButton.setEnabled(userTable.getSelectedRowCount() > 0);
				recommendUserBaseButton.setEnabled(userTable.getSelectedRowCount() > 0);
				recommendItemBaseButton.setEnabled(similarClassBox.getSelectedIndex() != 4 && userTable.getSelectedRowCount() > 0);
			} else if (event.getSource() == itemTable.getSelectionModel()) {
				similarItemButton.setEnabled(similarClassBox.getSelectedIndex() != 4 && itemTable.getSelectedRowCount() > 0);
				if (itemTable.getSelectedRowCount() > 0) {
					showInfluentialItemUser();
				}
			}
		}
	}