code: function( xpath, contextNode )
  		{
  			var node = this.selectSingleNode( xpath, contextNode ),
  				xml = [];
  			if ( node )
  			{
  				node = node.firstChild;
  				while ( node )
  				{
  					if ( node.xml )				// IE
  						xml.push( node.xml );
  					else if ( window.XMLSerializer )	// Others
  						xml.push( ( new XMLSerializer() ).serializeToString( node ) );
  
  					node = node.nextSibling;
  				}
  			}
  
  			return xml.length ? xml.join( '' ) : null;
  		}
docs: Gets the string representation of hte inner contents of a XML node,
  based on a XPath query.
  @param {String} xpath The XPath query to execute.
  @param {Object} [contextNode] The XML DOM node to be used as the context
  for the XPath query. The document root is used by default.
  @returns {String} The textual representation of the inner contents of
  the node or null if the query has no results.
  @example
  // Create the XML instance.
  var xml = new CKEDITOR.xml( '<list><item id="test1" /><item id="test2" /></list>' );
  // Alert "<item id="test1" /><item id="test2" />".
  alert( xml.getInnerXml( 'list' ) );