Geo Location Script

We want to be able to show different ads for different regions from one web page - we need the 'option' to set content to show for a particular country - It should be setup so that if we have a page and we only want people from the US to see that page and all other people see a different page then it should be able to do that. We have our own database that we get from [login to view URL] that you can use.