gistfile1.txt

private static UINavigationController _navigation;
		
		private static object navLock = new object();
		
		public static UINavigationController navigation
		{
			get{
				if(_navigation == null)
					lock(navLock)
						_navigation = new UINavigationController();
				
				return _navigation;
			}
			set{
				lock(navLock){
					_navigation = value;
				}
			}
		}