Google Map infowindow issue

I am facing a problem when working with Google map, I am trying to use a custom info window on google map with marker cluster. when I am creating a object of infobox class from marker cluster class then I am facing a error and the error is.

google.maps is undefined <br/>
infobox.js()infobox.js <br/>
InfoBox.prototype = new google.maps.OverlayView();

and I am using a

  ("scri开发者_StackOverflow社区pt src="http://www.google.com/jsapi" type="text/javascript" language="javascript"></script>) <br>

to load a Google map.

Please help me

I might lack some context info on your problem, but from what you provided, my guess is that you use the wrong call.

<script type="text/javascript" 
    src="http://maps.google.com/maps/api/js?key=_your_key_&sensor=false">

_your_key_ is to be replaced with what you obtain from your google code account. AFAIK, this might not be necessary, but just to be sure. If you leave it out, you still have to provide the sensor part.

A good starter for all this can be found here