I recently posted a thread asking how i could claculate the distance between two places using map co-ordinates and i recieved this very helpful answer.
You can use this line (your code will need to calculate $distance_across and $distance_up):
$distance = sqrt($distance_across$distance_across + $distance_up$distance_up);
my only problem now is how to calculate $distance_across and $distance_up what data do i use and how do i use it.
Any help would be greatly appreciated