private void AddButton_Click(object sender, RoutedEventArgs e)
        {
            if (Selection != null)
            {
                dynamic curWindow = null;
                var     selection = ((CurrentSelection)Selection);
                DbType  curDT     = GetDbTypeFromName(selection.Grid.Name);
                switch (curDT)
                {
                case DbType.Target:
                    curWindow = new TargetWindow();
                    break;

                case DbType.Product:
                    curWindow = new ProductWindow(Manager.GetAllItemsListOf <ProductTarget>());
                    break;

                case DbType.Task:
                    curWindow = new TaskWindow(Manager.GetAllItemsListOf <Product>());
                    break;

                case DbType.Employee:
                    curWindow = new EmployeeWindow(Manager.GetAllItemsListOf <CompanyTask>());
                    break;
                }
                if (curWindow != null)
                {
                    if (curWindow.ShowDialog() == true && curWindow.Data != null)
                    {
                        Manager.AddItem(curDT, curWindow.Data);
                    }
                }
                ClearSelectionAll();
            }
        }