function country_distance ($country1, $country2
{
$p1 = locate_country$country1);
$p2 = locate_country$country2);
return distance_on_earth$p1, $p2);
}
function country_distance ($country1, $country2
{
$p1 = locate_country$country1);
$p2 = locate_country$country2);
return distance_on_earth$p1, $p2);
}