[squid-users] how to block files in squid

[Nauman Yousuf]

acl FILE_MP3 urlpath_regex -i \.gz$ \.exe$ \.mp3$ \.tar.gz$ \.doc$
http_access deny FILE_MP3
i am using these two lines but seems its nor working b/c i download
tar files n exe file after that
what mistake i am doing