Is it better to disable a button or hide it?
Buttons. Disable the control to indicate that the user needs to do something first to “unlock” the functionality that this button performs. Buttons should never be hidden, because there is an expectation of persistence for them.
How do I hide a form field?
The <input type="hidden"> defines a hidden input field. A hidden field lets web developers include data that cannot be seen or modified by users when a form is submitted.