Llamar al archivo JavaScript en HTML
<script type="text/javascript" src="yourfile.js"></script>
SteDeus
<script type="text/javascript" src="yourfile.js"></script><script src="index.js"></script><script type="text/javascript" src="path-to-javascript-file.js"></script><script src = "index.js"></script><script src="Your-JavaScript-File.js"></script> <!--If JS file is in same folder with HTML file--> <script src="your js file"></script>