Custom classes best practices and eventListeners

Apologies ahead of time and thanks in advance for anyone who can provide guidance. First time posting in a forum, ever…but at least I managed to do it before i hit 40.

I’m trying to learn the effective use of custom classes. I want to develop a login screen that allows users to input a username and password and then verifies that they are registered. If they are registered, I want a main menu screen to appear with an “button” that allows them to view a “todo list”.

Currently, I have a custom class that creates the username_txt, password_txt, and submit_mc on stage (and adds an eventListener to the submit_mc). When clicked, the values of the usernam and password are fed into a php script to verify their existence in a database.

If “valid” is returned, i’m removing the login fields/button and loading another .swf that displays a “main screen”. The main screen has a button. If clicked, the button is supposed to display that user’s “todo list” (that will be pulled from the database based on who they are…some value returned from the original login process).

What is the best practice for accomplishing what I want to accomplish.

Is loading different SWF files for each part a good idea?

Are there eventListeners I should be using to know when different swf files have been loaded on stage since they may take time to load?

Are there things I should be aware of or warned about when doing this (benefits/limitations)?

Did I post this in the right place or is there somewhere else I should be posting?

Advice on posting more effectively in general (I know I’m wordy…better to start concise?)