
$squidlogtype - describe access.log format

if you log look like this
#squid native log
970313965.619 1249    denis.local TCP_MISS/200 2598 GET    http://www.emral.com/013.jpg userid  DIRECT

set $squidlogtype = 0;

if you log look like this
#emulated httpd log
192.168.3.40 - - [15/Apr/2005:11:46:35 +0300] "GET http://css.yandex.ru/css/mail/search.js HTTP/1.0" 200 4199 TCP_HIT:NONE

set $squidlogtype = 1;

for more info see 
emulate_httpd_log option in squid.conf