'*** LAT/LONG for Nashville International Airport (BNA)
lat1=36.12
Lon1=-86.67

'*** LAT/LONG for Los Angeles International Airport (LAX)
Lat2=33.94
Lon2=-118.40

'*** Units: K=kilometers  M=miles  N=nautical miles
Unit$ = "K"	

Result=HAVERSINE(Lat1,Lon1,Lat2,Lon2,Unit$)
R$=STR$(Result,"#,###.##")

PRINT "The distance between Nashville International Airport and Los Angeles International Airport in kilometers is: "&R$

STOP

DEF HAVERSINE(Lat1,Lon1,Lat2,Lon2,Unit$)
'---------------------------------------------------------------
'*** Haversine Formula - Calculate distances by LAT/LONG
'

'*** Pass to it the LAT/LONG of the two locations, and then unit of measure
'*** Usage: X=HAVERSINE(Lat1,Lon1,Lat2,Lon2,Unit$)

    PI=3.14159265358979323846
    Radius=6372.8
    Lat1=(Lat1*PI/180)
    Lon1=(Lon1*PI/180)
    Lat2=(Lat2*PI/180)
    Lon2=(Lon2*PI/180)
    DLon=Lon1-Lon2
    Answer=ACOS(SIN(Lat1)*SIN(Lat2)+COS(Lat1)*COS(Lat2)*COS(DLon))*Radius

    IF UNIT$="M" THEN Answer=Answer*0.621371192
    IF UNIT$="N" THEN Answer=Answer*0.539956803

  RETURN Answer

ENDDEF