Xml Namespace

I've loaded various xmlns through Url Loaders and sometimes you just can't parse them because you have to first import the namespace. Here's an example (cause I keep forgetting)

namespace media= "http://search.yahoo.com/mrss/"; //for flickr
use namespace media;
namespace media= "http://www.w3.org/2005/Atom"; //for Atom
use namespace media;