Sitemap error on Google webmaster tools

Need to provide an XML formatted sitemap file (sitemap.xml).

<?xml version='1.0' encoding='utf-8' ?>
<urlset xmlns='http://www.sitemaps.org/schemas/sitemap/0.9'>
    <url>
     <loc>http://myDomain.com</loc>
    </url>
    <url>
     <loc>http://myDomain.com/about.html</loc>
    </url>
    <url>
     <loc>http://myDomain.com/faq.html</loc>
    </url>
    <url>
     <loc>http://myDomain.com/careers.html</loc>
    </url>
</urlset>

make sure your sitemap doesn't contain BOTH of the following:

http://mydomain.com/ or http://www.mydomain.com/

AND

http://mydomain.com/index.html or http://www.mydomain.com/index.html