How to get Google Map coordinates by address ?

Greetings,

I've installed profile.module, gmap.module, gmap_location.module, I have Country and City fields in user's profile and I need to get GMap coordinates by these fields ... So, I don't want user to go to Location map page and enter his address to get coordinates I would like to do it automatically when user saves his profile information.

So, I want his Country and City fields concatinated together to be used as google address to receive coordinates and save them to location table. How can I do that ?

Thanks.