private void _btnTaskUpdateOnClick(object sender, EventArgs e) {
         if (listTasks.SelectedItems.Count == 0) {
            MessageBox.Show("Select task first", "Task not selected", MessageBoxButtons.OK, MessageBoxIcon.Stop);
            return;
         }

         var taskItem = (TaskListItem)listTasks.SelectedItems[0];

         var frm = new FrmDiagnosticsTaskAddUpdate(taskItem.Task.TaskId);
         frm.ShowDialog(this);
         _listTasksRefresh();
      }
 private void _btnTaskAddOnClick(object sender, EventArgs e) {
    var frm = new FrmDiagnosticsTaskAddUpdate();
    frm.ShowDialog(this);
    _listTasksRefresh();
 }