function addMarkerOpener($marker_id, $dom_id){
    	if($this->info_window === false || !isset($this->_markers[$marker_id]))
    	   return false;
    	if(!isset($this->_markers[$marker_id]["openers"]))
    	   $this->_markers[$marker_id]["openers"] = array();
        $this->_markers[$marker_id]["openers"][] = $dom_id;    	   
    }