PHP to convert longitude and latitude : I have loop that gives me a longitude and latitude for each client , I am looking for a function where I can pass these variables into and it will out northing and easting value.

I have tried gPoint class but no joy.
 
    Foreach ($clients as $client)
    {
                $client[lat]
                $client[long]
 
                Function convert($lat,$long)
    }
