function check_GeoLocation($gps_user,$gps_spot,$r){

    if($r==0){

       return 1;

    }

    if(count($gps_user)>1){

    $gps_user[0]=$gps_user[0]*pi()/180;

    $gps_user[1]=$gps_user[1]*pi()/180;

    $gps_spot[0]=$gps_spot[0]*pi()/180;

    $gps_spot[1]=$gps_spot[1]*pi()/180;



    $dlat=$gps_user[0]-$gps_spot[0];

    $dlon=$gps_user[1]-$gps_spot[1];

    $a = pow((sin($dlat/2)),2) + cos($gps_user[0]) * cos($gps_spot[0]) * pow((sin($dlon/2)),2);

    $c = 2 * atan2( sqrt($a), sqrt(1-$a) );

    $d = 6373 * $c;




    if($d<=$r){

      return 1;

    }else{

      return 0;

    }

   }else{

      return 0;

   }

}

?>