add tabs and convert the tab to javascript

I have a website (see below) that I want some modifications [login to view URL] 1. adding tabs inside the content. For example, if you are looking at the "about us" section, you can see other tabs like "management", "contact us" under the same category in the content. see the attachment. 2. convert the tab to an external javascript file. so if I want to modify something, I don't have to go back to modify each individual pages.