comparing arrays then adding commmon elements to a thrid array

[twisted 128]

so i want to count all towns between to bases(also towns). I figured out a way which would be by finding all towns near the 2 bases and then sorting out and only keeping the towns common to both. but whne i try i get an error.

{if _x in _townsby1 then {_commontowns se> Error position: Error if: Type Location, expected Bool

_dist = _firsttown distance _secondtown; _townsby1 = nearestLocations [_firsttownpos, ["NameVillage","NameCity","NameLocal","NameCityCapital","CityCenter","Airport"], _dist];  _townsby2 = nearestLocations [_secondtownpos, ["NameVillage","NameCity","NameLocal","NameCityCapital","CityCenter","Airport"], _dist];  // now get all towns common to both lists  _commontowns = [];  {if _x in _townsby1 then {_commontowns set[count _commontowns, _x]; }} foreach _townsby2;

edit - dope. i forgot to put brackets around the if statement. very embaressing.

Edited February 28, 2014 by twisted
aaaaargh