Be careful when you reference the location of the JavaScript file. You can place them in a separate directory and then reference them all from there, e.g., /javascripts/popUps.js. An important tip to remember is that, when placed within the Web page itself, the script is enclosed in a different type of script tags.There you have it.ou can place them in a separate directory and then reference them all from there, e.g., /javascripts/popUps.js. An important tip to remember is that, when placed within the Web page itself, the script is enclosed in a different type of script tags. There you have it.