my $B1 = 7.2167121725093;
my $L1 = 51.4840049423119;
my $erdradius = 6378.388;

my $prepare_sth = "select primarykey, name from defaultusers where status = 'N' and ";
$prepare_sth .= "(ACOS((SIN(RADIANS($B1))*SIN(RADIANS(lat))) + (COS(RADIANS($B1))*COS(RADIANS(lat))*COS(RADIANS(lon)-RADIANS($L1)))) * $erdradius) <= 100";