how to restrict result to a country in Geocoding via HTTP Requests

http://maps.google.com/maps/geo?q=%E5%93%88%E5%AF%86%E6%9C%BA%E5%9C%BA&output=xml&gl=CN

My search condition is a airport in China, But its result is not. Is
there any parameter to restrict the result in China.

In google map api v3's doc, no api is provided for Geocoding via Http
request.

--
You received this message because you are subscribed to the Google Groups "Google Maps API" group.
To post to this group, send email to google-maps-api@googlegroups.com.
To unsubscribe from this group, send email to google-maps-api+unsubscribe@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/google-maps-api?hl=en.