jQuery Grid Plugin - jqGrid

It's depend on how you implemanted your master/detail example. The natural way could be place in the country grid onSelectRow event. In the event handle you could change some parameters of details grid (city grid) like title, url with respect of setCaption, setGridParam or some other methods. Then you call trigger(“reloadGrid”) on details grid. You can also use getRowData inside of event handle to get all information from selected master row.

All logic about reading latitude/longitude from the parent (country) can do your server.

If you don't have any server part of your program, you could do all works in javascript also.

I recommend look at http://trirand.com/blog/jqgrid.....qgrid.html choose Advanced and "Master Detail".

Best rebards
Oleg

Ohhh. This question is really not for the jqGrid forum! But you can fill city-table based on SQL statement like

SELECT
    name,
    CASE WHEN city.lat IS NULL
         THEN country.lat
         ELSE city.lat
    END,
    CASE WHEN city.lon IS NULL
         THEN country.lon
         ELSE city.lon
    END,
FROM city
    INNER JOIN country ON city.countryId=country.id

Regards
Oleg