I have on my website, www.pixelumneo.bravehost.com 2 ads showing but if you click on the birthdays link there is only one ad. Did I mess up the html? How can I get rid of the extra ad on the homepage?

The page with the double ads has two tags, one without the background reference and one with. There should only be one tag on a page. Remove the one without the background reference.

All of the attributes have been depreciated, but most browsers will understand them for some time. Eventually, however, newer browsers will not. It's better to move your background definition to the body style setting that you have, right after the tag. See W3Schools - CSS Background for details.

Thanks!