The Oldenburgs ended with Frederik 7 as he didn't have any children, therefore he adopted a distant relative, Christian, who was made king Christian 9 in 1863 when Frederik 7 died. And Christian 9 belonged to the
Schleswig-Holstein-Sonderburg-Glücksburg family. So Danish royalty started afresh with Christian 9 and the Glucksburgs. Since that is a very long name, they normaly use Glucksburg. And that is the the family line that the Danish royal family belong to today, and it also is the family line of the Norwegian royal family.
This has confused me several times, but I figured it out by reading "Haakon and Maud - Kongstanken" by Bomann-Larsen (a Norwegian author) and for this post I've used
www.wikipedia.org (
http://en.wikipedia.org/wiki/Frederick_VII_of_Denmark and
http://en.wikipedia.org/wiki/Christian_IX_of_Denmark)