private void btnCreateTour_Click(object sender, RoutedEventArgs e)
{
decimal defaultCost = 100;
gt = new GroupTour(txtTourName.Text);
gt.UpdateTotalCost(defaultCost);
lblTourName.Content = txtTourName.Text;
btnCreateTour.IsEnabled = false;
}
private void btnLocation_Click(object sender, RoutedEventArgs e)
{
gt.AddLocations(txtLocation.Text);
gt.UpdateTotalCost(200);
lstvwlocation.Items.Add(txtLocation.Text);
}