vb6 math lat long distance calculation

i want a function in vb6 to calculate as accurate as possible the distance between 2 lat and long co-ords the result will be in meters distance eg: Public Function LLDistance(lat1 As Double, lat2 As Double, long1 As Double, long2 As Double) As Double latitude and longitude will be in decimal format, such as lat = 54.58117 lon = -5.98808 function must cater for -ve values ie lat/long can be +ve or -ve decimal values for example code see: [login to view URL] [login to view URL] ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows? (depending on the nature? of the deliverables): a)? For web sites or? other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software? installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform vb6