I started coding a considerably complicated web application, and it became quite a mess. So I figured I'd try to organize it in a better way. MVC seemed appropriate. I've never used MVC before, and researching about it I'm trying to consolidate a better perception of it (and my questions obviously reflect what I think I've learned so far). My questions are slightly JavaScript oriented:

1. What object should make "AJAX" requests? The Controller or the Model? (seperation -- should the Model just store/manipulate the data, should it not care/know where the data came from, or should it be the one fetching it?)

2. Should the Model call View functions providing them with data as arguments or should the View query (reference) the Model within itself? (seperation principles in mind, "the View shouldn't care/know where it gets the data from" -- is that correct?)

3. In general, should the View "know" of the Model's existance, and vice-versa? Is the Controller the only thing gluing them together or is that simply incorrect? (I really doubt that statement is generally correct)

There's a good chance I'd want to port this into a desktop/mobile application, so I would like to seperate components in a way that will allow me to achieve that task, replacing the current source of the data, HTTP requests, with DB access, and replacing the View.

Maybe every approach that I've asked about is still "valid" MVC and it's just up to me to choose. I understand that nothing is set in stone, I'm just trying to have a (better) general idea in my head.