Get data from XML : Check the namespace

Hi,

I want to check that the namespace of the XML file I want to load is the right one.
Does anybody have a quick sample on that?

I've tried ../../../*[name()='Document@xmlns'] with a loop xPath like /*[name()='Document']/*[name()='Level1']/*[name()='Level2'] but I can't get anything.

Thanks!
Regards,

Jer