How to add menu to all the pages of website?

I have folder, that contain my web-site. Every page of site have menu. But examle of my problem the next: I create new page new.html in this folder similar my old page old.html, add link to the page in menu. Then I go to old.html, click on link of new.html, and then get new.html without menu. Why is it problem exist, if new.html similar to old.html?