Web Application Multiple screen

Hi to all

I'm very very new on Flash builder so my question can be very silly ....

I'm trying to buil my first web application that is composed by 4 screen

In the first screen there are 3 button and I want display the rigth screen when user click on the button

I found on internet this code

navigator.pushView(SecondScreen);

and I associated it on click event

but i get the error

Can someone help me ?

thank's in advance

Multiple markers at this line:

-1061: Call to a possibly undefined method pushView through a reference with static type spark.components:NavigatorContent.

-1136: Incorrect number of arguments. Expected 1.

-1 changed line