private void btn_DeleteSubtask_Click(object sender, RoutedEventArgs e)
{
if (this.SelectedSubtask != null)
{
var assignmentLogic = new AssignmentLogic();
assignmentLogic.DeleteSubtask(this.Assignment.Id, this.SelectedSubtask.Id);
assignmentLogic.Dispose();
Load(this.Assignment.Id);
RefreshBindings(this.PagingManager.CurrentPage);
}
}