Showing text field while focus is on a specific text

Hi everyone.

I’m completely new to scripting in PDF files, and really had a hard time figuring out where to start. I read a couple of tutorials, but i still couldnt figure out how to do what i wanted. I’ve got a .pdf file with a bunch of text fields, i would like it to make it so that when the user has focus (is writing in or clicked it) on of the fields it shows a different field with information on how to fill out that field and which field to procede to. Ive figured out how to show a field when focus is on another field, but cant get it to hide again when focus goes to something else.

If anyone could point me in the right direction or to a similar post or anything remotely familiar it would be greatly appriciated

Not familiar with PDF coding but in other tools we use opposite actions so perhaps these will help.

HTML/Javascript
within an HTML form I can use onFocus and onBlur
<input type=“text” name=“somename” onFocus=“function()” onBlur=“anotherFunction()” />

CSS
a:link vs a:active vs a:hover vs a:visited are different states of the anchor tag.
combine with display attributes like background-color

<a href=“someurl.com”>click me</a>

a {display:block;}
a:link{background-color: white;}
a:hover{background-color: pink}