import flash.net.SharedObject;

var so:SharedObject = SharedObject.getLocal("userData");

so.data.username= "user1377";
so.data.uid= new Number(1337);

// create object to store data
var obj:Object = new Object();
obj.prop = "value";

so.data.userobj= obj; // store custom object in SharedObject

so.flush(); // writes changes to disk

This is just a basic SharedObject snip, access/store data locally.

Basic Local SharedObject

ActionScript 3