How it works underneath?

Hello,

I came to a problem with setting session variables. Let’s say I have two pages (A and B) and other subpages of both of them. There is a snippet call in the content of A and B which sets a session variable to a value of A and B. After setting those values there is a second snippet call - FirstChildRedirect. The idea is just to set the session variable and navigate to the subtree of A or B.
What happens is that when navigating to B the user finally gets to the page B1 (subpage of B). When I refresh the page B1 I can see that the session variable is set to A !!!! Yes to A !!!
So what must have happened - somehow MODx executed the snippet on page A ! Why? How can I check what is going on underneath? Could it be caused by a snippet? Can I turn on some loggin to see what is happening?

How to avoid executing page A while displaying B/B1?

Maybe I should manage my session variable in a different way?

Sorry for duplicating. But this post also catains another question. - how modx works underneath? Is there some kind of description for that?

And thanks for Your answer to my other post.

Greg

For a dive into learning MODx in general I suggest visiting the resources available on http://modxcms.com/learn/it.html