I need a PHP script to be used on my Wordpress blog on aviation industry. The script should calculate the distance between airports in flight miles. User will be selecting Origin country and the airports in the origin country should be listed in drop down (and/or might be a smart suggestion text box). Same is true for destination country and destination airport. When the selection is done, the script should calculate the distance between the two airports on a new page.
The result pages should be SEO optimized.
There is a DB available with more than 9000 airports worldwide, with Geo-locations which are necessary for the computation.