Retrieves a node specified by local name and namespace URI.
Per [XML Namespaces] , applications must use the value null as the namespaceURI parameter for methods if they wish to have no namespace.

Parameters:

namespaceURI		The namespace URI of the node to retrieve.
localName		The local name of the node to retrieve.

Returns:  A Node (of any type) with the specified local name and namespace URI, or null if they do not identify any node in this map.

Exceptions:

DOMException

NOT_SUPPORTED_ERR: May be raised if the implementation does not support the feature "XML" and the language exposed through the Document does not support XML Namespaces (such as [HTML 4.01]).

Since:  1.4, DOM Level 2