I need help finishing adding a new field...

This is where I am:

I am a notice. I am using Dreamweaver. I have a site set up, testing server set, and am connected to the database via Dreamweaver.

1. I created my new field in mySQL (CompanyName) - see mysql photo attachment

2. I added my Company Name Text field to the user registration form - see userregistration attachment. Even though I added the field in dreamweaver and dragged the userCompanyName from the bindings into the field I don't think I am doing it right. Actually it's not correct bc the info is not saving to my database when I register a test user. My code is
<?php echo((isset($_POST["UserCompanyName"]))?$_POST["UserCompanyName"]:"") ?>. The code to another field and similar to all other fields is as follows:
<?php echo(ValidatedField("usersRegistration","UserFax")) ?>

What window would I use to get this code and add it to the Company Name text field to make it work and save to the database.

3. I added the field to the userProfile page as well, but not sure what window to use to add get the correct GET php code. See my attachment.

Can someone point me in the right direction with some clear instructions? This is my first time actually going into a database and updating it and using the database connection in dreamweaver.

This is my url if you need to look at that:
users_Registration.php

I would like to take it one step at a time, but I would also like to add check boxes with different categories that the registrant will be able to pick up to 5 categories to be listed in. Would this be similar to adding the new text field above and what would the php code (or whatever code) be to limit their choices during registration?

If you need additional information please let me know, but be clear on what you need b/c like I said I am not familiar with the coding language in mySQL and php.

Thank you,
Ernie