While trying to get this quickstart to work I keep getting a 
MappingException: "XML validation error: Could not find schema 
information for the element 'urn:nhibernate-mapping-2.0:hibernate-
mapping" when calling cfg.AddAssembly("DBSandbox").

My mapping file looks like the following:

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
  <class name="DBSandbox.Movies.Movie, DBSandbox" table="Movies">
    <property name="Id" type="Int32"/>
    <property name="Title" type="String" length="50"/>
    <property name="Rating" type="String" length="10"/>
    <property name="Actors" type="String"/>
  </class>
</hibernate-mapping>

Thanks in advance for any help.