Yes, your own code is probably fine. Geocities is a free service that comes with ads; the HTML/javascript these ads are written in is *generally always* bugged and has errors. Hence you get errors reported when you view the pages even though your
own page is fine. The code to display the advertisements is added automatically to the bottom of your pages by Yahoo (though sometimes it puts it at the top).
There is a line you can add which suppresses the error
reporting; but it requires editing the webpage HTML to add in this line
yourself, plus you need to re-upload each webpage every so often as sometimes the geocities ad code is inserted at the top of a page rather than the bottom (so it comes before the instruction to block errors). I note your pages are created in a MS Office package and using Yahoo Pagebuilder but let me know if you want the code to block errors if you fancy adding it in. The errors are just one of the things that come with the Geocities service.
Hope that clarifies if not helps.