Thankfully, using JavaScript to create this effect isn’t that difficult. In this article, I’m going to show you how to write the JavaScript code for a rollover, step by step.

John Mueller from Google advises placing JavaScript code underneath the HTML element to ensure that search engines can clearly understand your website.

I wrote a small javascript function to show images in a popup window. The code is below.function imgpop (imgLocation) { img = new Image (); img.src = ...