Since I’m very new to HTML and JavaScript, I wonder if there are possibilities for popups like the alert() popup? As I think I figured out, there are three predefined popups in JavaScript, alert(), confirm() and prompt(). But I want to make a custom popup, with HTML code in it, but I have no idea how to approach to this.
Are there methods in JavaScript itself to override the look of a popup, or do I neet to import certain packages to achieve this?
Sounds like you need a lightbox and not necessarily a pop up window. There are plenty around and if your using jquery then that has many free jquery lightbox plugins available.
You can see here for plenty of examples, I personally like jQuery lightbox plugin.