private void MiModifyPM_OnClick(object sender, RoutedEventArgs e) {
			if (lvPersonMatter.SelectedIndex != -1) {
				ModifyAndAddMatterWindow modWindow = new ModifyAndAddMatterWindow(this,
					ModifyAndAddMatterWindow.MODIFY_PERSON_MATTER, "", pmDataTable.Rows[lvPersonMatter.SelectedIndex]["pm_id"].ToString());
				modWindow.tbTitle.Text = pmDataTable.Rows[lvPersonMatter.SelectedIndex]["pm_title"].ToString();
				modWindow.tbContent.Text = pmDataTable.Rows[lvPersonMatter.SelectedIndex]["pm_content"].ToString();
				modWindow.Show();
			}


		}
			void mod_Click(object sender, RoutedEventArgs e) {
				if (mainWindow.lvGroupMatter.SelectedIndex != -1 && ((ComboBoxItem)mainWindow.cbGroup.SelectedItem).Name == "cbiOwn") {
					ModifyAndAddMatterWindow modWindow = new ModifyAndAddMatterWindow(mainWindow, ModifyAndAddMatterWindow.MODIFY_GROUP_MATTER,
						mainWindow.savedGroupId, 
						mainWindow.gmDataTable.Rows[mainWindow.lvGroupMatter.SelectedIndex]["gm_id"].ToString());
					modWindow.tbTitle.Text = mainWindow.gmDataTable.Rows[mainWindow.lvGroupMatter.SelectedIndex]["gm_title"].ToString();
					modWindow.tbContent.Text = mainWindow.gmDataTable.Rows[mainWindow.lvGroupMatter.SelectedIndex]["gm_content"].ToString();
					modWindow.Show();
				} else if (mainWindow.lvGroupMatter.SelectedIndex != -1 && ((ComboBoxItem)mainWindow.cbGroup.SelectedItem).Name != "cbiOwn") {
					MessageBox.Show("You can just modify matter of the group owned by you!");
				}
			}
		private void BtnAddPM_Click(object sender, RoutedEventArgs e) {
			ModifyAndAddMatterWindow addWindow = new ModifyAndAddMatterWindow(this, ModifyAndAddMatterWindow.ADD_PERSON_MATTER, "", "");
			addWindow.Show();
		}
			void add_Click(object sender, RoutedEventArgs e) {
				if (mainWindow.lvGroup.SelectedIndex != -1 && ((ComboBoxItem)mainWindow.cbGroup.SelectedItem).Name != "cbiNotin") {
					ModifyAndAddMatterWindow addWindow = new ModifyAndAddMatterWindow(mainWindow,
						ModifyAndAddMatterWindow.ADD_GROUP_MATTER,
						mainWindow.savedGroupId, "");
					addWindow.Show();
				} else if (mainWindow.lvGroup.SelectedIndex != -1 && ((ComboBoxItem)mainWindow.cbGroup.SelectedItem).Name == "cbiNotin") {
					MessageBox.Show("You have no right to add matter to the group you are not in!");
				}
			}