Thanks for help Simon!
Using your help, I get the number of the last page, and the first too.
The first page, I got on the "onEnter" and the last page I got on the "onExit".
Now, I need to use this both informations together, to write a stream like this:
for(var i = firstPage;i<=lastPage;i++)
{
stream.write( "Intro ...." + i + "\n");
}
I can do it with xpath or something?