Show/hide forms using buttons and JavaScript

Question

I need to show a form using a button, and hide it when the user presses another button, because the other button shows another form. I did a similar thing with a select box,

Answer 1

There's the global attribute called hidden. But I'm green to all this and maybe there was a reason it wasn't mentioned yet?

var someCondition = true;

if (someCondition == true){
    document.getElementById('hidden div').hidden = false;
}

https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/hidden