How to run/load a separate javascript file selectively from inside javascript?

Question

I have 3 JavaScript files that I would like to load from an index.html file. I\'m choosing among them by using if statements which I only know how to d

Answer 1

var s = document.createElement("script");
s.src="myscript.js";
document.head.appendChild(s);

Oh man, so many same answers at the same time.