Dynamic JavaScript Menus for HTML

My client’s brochure-style site is built entirely in static HTML. Each of the 60+ pages carries a duplicated top and side menu, so every time we add or remove a product I have to open every file and manually paste the new navigation... (Budget: $250 - $750 USD, Jobs: CSS, Frontend Development, HTML, HTML5, JavaScript, User Interface / IA, Web Design, Web Development)