Range in one drop down list depended on the selection in another drop down list

Hi,

I have a report showing product prices at diffrent location. At the top of the report there is two drop down lists - One with all the locations and the other one with all products in our supply system.

The bad thing is that from the second list I can choose any product regardless of were it's located and the result will then of cours be N/A if I in the data list don't have any price for that product on that location, i.e we don't sell that product on that location.

What I would want is that the range of products shown in the second drop down list were dependent on the selected location in the first drop down list.

Please see the example I have attched on how the file is built today.

Thanks!!
//Martin