I'm working with some code that has a standard FORM and Submit button, with the associated x.php to process the fields.

But there's also Javascript that refers to a certain section on that form, but which has an Ajax() $_POST call to another url y.php.

Is that proper?  Since this is essentially a Submit (I think) to one form inside another form with a different submit module, is that considered a nested form?  

I don't even know if nested forms are ok in php, to begin with, aside from the javascript.

Do I need to further clarify?