You do realize that you don't need to program anything or add any code or do anything other than just edit the page settings, right? It's fairly simple. Page Name is what appears in the menu and Page Title is what appears in the <title> tags. Setting this in the page settings overrides the default admin settings for page title. If you don't set Page Title in the page settings, then the Page Name is used I think along with the website name from the admin settings. The Page Name and Page Title don't have to be the same thing, so you can have a longer page title for the <title> in the <header>, but a shorter name for the menu to avoid a page name that is just too verbose to fit nicely in the menu.
Not sure why anyone would recommend special code unless I'm missing the point. If you are actually trying to have the page name randomly change by dynamically generated text each time the page is entered, well, I would think that would cause more issues with SEO than actually help, unless randomly changing page names are something the search engines like now. I think frequently updated content would be better and a lot less apt to be harmful to your ratings. If your content is so changing and different each time you post that a new page title is in order, then you're likely better off from an SEO standpoint adding a new page for this new and unique content.
There is also a third party module that does update the keywords tag to include words and phrases from the pages content, and something like that might be helpful to you. I'm not sure if it works with DNN5, though, as I used it as a Pageblaster plugin and haven't gotten Pageblaster to behave with DNN5 yet. I never saw any help from it, though it could be helpful.