how to attach a javascript file to html code example
Example 1: include script in html
<script type="text/javascript" src="/path/to/script.js"></script>
Example 2: link javascript to html
<script src="index.js"> </script>
Example 3: how to link js to html
<script src="Your-JavaScript-File.js"></script> <!--If JS file is in same folder with HTML file-->
Example 4: calling javascript file in html
<script type="text/javascript" src="yourfile.js"></script>