Looking for JavaScript to add blank page to a form

Hello, Community! I'm a novice programmer and new to JavaScript. I've been crawling the web for the past several hours to find JavaScript that I can use to add a blank page with a single large (page-filling) text box. The use case is that on my form, there's a text input box for users to add comments to the form. If they need to add a lot of text, though, the auto-sizing feature makes the text eventually too small to read. My proposed solution is to set a fixed size to the input box font and provide a button to add a second page with a fillable text box.

I've tried entering this single-line command in the button's "Run a JavaScript" Action box:

this.newPage(1);

Clicking the button in the form does not add a page - nothing happens...no error, just...nothing.

I've tried this code: 

var A = this.getTemplate("Short Form");
A.spawn(2,false,false);
this.pageNum=1;

 Same result - nothing happens.

I'm not putting this code inside braces what you see is exactly what I put in the box.

During my webcrawl, I found hints that the page may not generate if nothing is added to it, but I also am not sure that the code is to add my desired box. Maybe the solution is that either will work if I then add code to put the text box in place. 

Any pointers? Remember, I'm new to coding, so if there are customary pieces of code required to make code run, I don't know that... 🙂