attach javascript file to html code example
Example 1: import js in html
<script type="text/javascript" src="yourfile.js"></script>
Example 2: linking a script .js
<script type="text/javascript" src="path-to-javascript-file.js"></script>
Example 3: import script html
<html>
<head>
<script type="text/javascript" src="/path/to/script.js"></script>
...