Referring to a variable within a class

1

Ok, so I have found a tutorial which shows me how to create a class. It also shows me how to construct an object in the main code. What I want to do is to access a variable from the object that I made. Heres the code…

This is the link to the tutorial:
http://flash.lillegutt.com/?p=29

the Car.as file:

package  
{  
public class Car  
{  
	// defining attributes to the car  
	private var _name:String = "My custom Porche";  
	private var _engine:Number = 6.3;  
	private var _numberWheels:int = 4;  
	private var _doors:String = "Elevating doors";  
  
	// The Car constructor  
	public function Car(name:String="custom car", engine:Number=0, numberWheels:int=4, doors:String="")  
	{  
		// setting the global attributes to the incoming variables  
		_name = name;  
		_engine = engine;  
		_numberWheels = numberWheels;  
		_doors = doors;  
	}  
}  
}

Then I use this code to construct the object, which in this case is a car (the code is in my main flash file):

var mycar:Car = new Car("Porche", 3.2, 4, "Normal doors");

I understand all of the code, but how do I reference a variable like the engine? I have tried lots of things like “trace(this[mycar].engine)”, "trace(mycar.engine) but nothing seems so work. I just get error messages of property undefined.

Any help would be really appreciated, thanks.