If I do this inside a User Control:
NavigationService.Navigate(new Uri(\"/Alliance.xaml\", UriKind.Relative));
it says this error:
NavigationService is a class. Navigate is a method you can call on instances of that class. It is not a static method you can call from outside an object reference.
Basically you need to get the current NavigationService for the current page. This link http://msdn.microsoft.com/en-us/library/system.windows.navigation.navigationservice.aspx should help.