function tag_open($parser, $tag, $attr)
    {
        $this->_currentTagContents = '';
        $this->currentTag = $tag;
        switch($tag) {
            case 'methodCall':
            case 'methodResponse':
            case 'fault':
                $this->messageType = $tag;
                break;
                /* Deal with stacks of arrays and structs */
            case 'data':    // data is to all intents and puposes more interesting than array
                $this->_arraystructstypes[] = 'array';
                $this->_arraystructs[] = array();
                break;
            case 'struct':
                $this->_arraystructstypes[] = 'struct';
                $this->_arraystructs[] = array();
                break;
        }
    }