I'm trying to make POI's InfoWindow close when click a link.
I overrided the setContent of InfoWindow like this:
//override the built-in setContent-method
google.maps.InfoWindow.prototype.setContent = function (content) {              
    content = content.innerHTML + '<br/> <a href="#" onclick="onSavePlace();">Save place</a>';
    //run the original setContent-method
    fx.apply(this, arguments);
};
Note: I didn't create any InfoWindow object to reference to use close() method.