With each new page I have to update the navigation panel. Which means I go from page to page copying and pasting my navigation bar. The more pages I add the harder it gets.
If your page is strictly HTML+JavaScript, you can use HTML DOM innerHTML Property. Here is an example:
index.html
rest of web page body here
about.html
rest of web page body here
script.js
document.getElementById("navMenu").innerHTML =
'';
Important line here is nav tag, and all you need to do is to add this line in other pages in this example about.html.
I also recommend PHP or similar to accomplish what you need!