windows phone

[man.chester.581]

im trying to creat buttom to show all ocntacts on the phone

with this code :

    private async void SearchContactButtom_click(object sender, RoutedEventArgs e)
    {
    await SearchContacts();

    }

    private async Task SearchContacts()
    {
        var contactsStore = await ContactManager.RequestStoreAsync();
        IReadOnlyList<Contact> contacts = await contactsStore.FindContactsAsync();
        var dlg = new Windows.UI.Popups.MessageDialog("found " + contacts.Count + "contacts :D");
        await dlg.ShowAsync();
        ContactsListView.ItemsSource = contacts;


    }

and this xaml code

      <Page.Resources>

    <DataTemplate x:Key="ContactDataTemplate">
        <StackPanel>
            <TextBlock Text="{Binding Dispatcher}" />
        </StackPanel>
    </DataTemplate>
</Page.Resources>

<Grid>
    <Button Name="SearchContactsButtom"
        Content="Button"
            HorizontalAlignment="Left"
            VerticalAlignment="Top" 
            Click="SearchContactButtom_click"
            />

    <ListView Name="ContactsListView" Margin="-10,73,10,-73"/>
</Grid>

but i have error package could not be registerd
and i think there is mistake i did at the datatemplate tage on the xaml code at the binding line
any ideas ??
Thx