Question: I'm a "long time reader first time poster", glad to start participating in this forum.

My experience is with Java, Python, and several audio programming languages; I'm quite new to the big bad web technologies: HTML/CSS/JavaScript. I'm making two personal sites right now and am wondering if I'm relying on JavaScript too much.

I'm making a site where all pages have a bit of markup in common--stuff like the nav bar and some sliced background images--so I thought I'd make a pageInit() function to insert the majority of the HTML for me. This way if I make a change later, I just change the script rather than all the pages. I figure if users are paranoid enough to have JavaScript turned off, I'll give them an alert or something. Is this bad practice? Can JavaScript be overused?

Thanks in advance.

Answer: 
What you do is more of a job for server side ~~scripting~~ preprocessing in languages like PHP (or Python, or Java... actually there's server side JavaScript possible as well). This way you can deliver the content no matter if the browser supports JavaScript or not. Use JavaScript to do what server side technologies can't (image rotation, dynamic menus, AJAX calls etc).
Its pretty bad. Consider Search Engine Optimization (SEO). Where do you get info for that pageInit()? AJAX call or just some static text?