Save data to PersistanceManager or SharedObject

Question

import spark.managers.PersistenceManager;


var persistenceManager: PersistenceManager = new PersistenceManager();
persistenceManager.setProperty('Story1', counter_stories);
persistenceManager.save();

Error message: Can not find spark.managers:PersistenceManager.

I like to save data in adobe flash action script for mobile app in this way. It contains several counters and numbers.

Maybe using a local Shared Object is a better way to do this?