private void ListViewMenu_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            int index = ListViewMenu.SelectedIndex;

            // Array[]int= new Array[//];
            MoveCursorMenu(index);

            switch (index)
            {
            case 0:

                GridPrincipal.Children.Clear();
                GridPrincipal.Children.Add(new Crawling(Query.Text, Language.Text, Source.Text));

                break;

            case 1:
                //if(index)
                GridPrincipal.Children.Clear();
                GridPrincipal.Children.Add(new Filter(Query.Text, Language.Text, Source.Text));
                break;

            case 2:
                GridPrincipal.Children.Clear();
                GridPrincipal.Children.Add(new Ranking(Query.Text, Language.Text, Source.Text));
                break;

            case 3:
                GridPrincipal.Children.Clear();
                GridPrincipal.Children.Add(new Recommendation(Query.Text, Language.Text, Source.Text));
                break;

            case 4:
                GridPrincipal.Children.Clear();
                GridPrincipal.Children.Add(new Report());
                break;

            case 5:
                GridPrincipal.Children.Clear();
                GridPrincipal.Children.Add(new History());
                break;

            case 6:
                GridPrincipal.Children.Clear();
                GridPrincipal.Children.Add(new StarRating());
                break;

            case 7:
                GridPrincipal.Children.Clear();
                GridPrincipal.Children.Add(new About());
                break;

            case 8:
                Welcome welcome = new Welcome();
                welcome.Owner = this;
                this.Hide();
                welcome.ShowDialog();
                break;

            default:
                break;
            }
        }