UUGH registerClassAlias

programming flash
1

I’m trying to save an an array of objects of the class type Engine into a shared object.
To make sure that each engine object doesn’t revert to an anonymous object as soon as the player closes(so loosing its specific properties) I think I need to register a class alias.
I do not know how or where to do this as I don’t know what the H is going on(do I sound frustrated)
How and where would I do this?

public function saveGame(e:Event):void
        {
            var sharedObject:SharedObject = SharedObject.getLocal("rwmScores");
            trace("Application saveGame");
            
            sharedObject.data.engineType = _model.engineType;
            sharedObject.data.shipHealth = _model.shipHealth ;
            sharedObject.data.shipFuel = _model.shipFuel ;
            sharedObject.data.day = _model.day;
            sharedObject.data.cash = _model.cash;
            sharedObject.data.cargoOnBoard = _model.cargoOnBoard ;
            sharedObject.data.oreOnBoard = _model.oreOnBoard;
            sharedObject.data.oreTypeOnBoard = _model.oreTypeOnBoard;
            sharedObject.data.hsiVsiBought = _model.hsiVsiBought ;
            //sharedObject.data.purchasedEngines = _model.purchasedEngines.slice();
             [COLOR=#ff0000]//registerClassAlias("engineAlias",Engine);??????????????????[/COLOR]
            for (var i:Number = 0; i < _model.purchasedEngines.length;i++ )
            {
                
                trace( "A174 engineNames " + _model.purchasedEngines*._engineName);
                sharedObject.data.purchasedEngines*:new Engine();
                sharedObject.data.purchasedEngines* = _model.purchasedEngines*;
                trace("a176 data.purchEng " + sharedObject.data.purchasedEngines*);
                trace("a177 data.purch._engineName "+sharedObject.data.purchasedEngines*._engineName);
            }
            //trace("a205 pruchasedEngines.length=" + _model.purchasedEngines.length);
            
        
        sharedObject.flush();
        }