public function getChildren( $nodeName = NULL )
	{
		if( !$nodeName )
			return $this->children;
		$list	= array();
		for( $i=0; $i<count( $this->children ); $i++ )
			if( $this->children[$i]->getNodeName() == $nodeName )
				$list[]	= $this->children[$i];
		return $list;
	}