How to convert a javascript code to SQL stored procedure

Can anyone help me to conver the following javascript code to SQLSTOREDPROCEDURE. I am not an expert to write stored procedure. I want to make a stored procdure to find distance between two postcodes:

var R = 6371; // km
var dLat = (lat2-lat1).toRad();
var dLon = (lon2-lon1).toRad(); 
var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
        Math.cos(lat1.toRad()) * Math.cos(lat2.toRad()) * 
        Math.sin(dLon/2) * Math.sin(dLon/2); 
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
var d = R * c;

I got this from http://www.movable-type.co.uk/scripts/latlong.html
Please see the section for Distance.

Thanks a lot.