function distance(lat1, lon1, lat2, lon2, unit) {
	var radlat1 = Math.PI * lat1/180
	var radlat2 = Math.PI * lat2/180
	var radlon1 = Math.PI * lon1/180
	var radlon2 = Math.PI * lon2/180
	var theta = lon1-lon2
	var radtheta = Math.PI * theta/180
	var dist = Math.sin(radlat1) * Math.sin(radlat2) + Math.cos(radlat1) * Math.cos(radlat2) * Math.cos(radtheta);
	dist = Math.acos(dist)
	dist = dist * 180/Math.PI
	dist = dist * 60 * 1.1515
	if (unit=="K") { dist = dist * 1.609344 }
	if (unit=="N") { dist = dist * 0.8684 }
	return dist
}      // JScript File

function CalcDist(lat1, lat2) {
    var rad = 180 / Math.PI;
    distmiles = 3960 * Math.acos(Math.cos((90 - lat1)/rad) * Math.cos((90 - lat2)/rad) + Math.sin((90 - lat1)/rad) * Math.sin((90 - lat2)/rad) * Math.cos((1 - 1)/rad));
    return distmiles;
}