[squid-users] replace all .swf with local .gif (blocked.gif)

Hello
We are on openbsd system (4.3)
With Squid 2.6 and jesred 1.2.1, how can i replace all .swf with the
image : blocked.gif ?

In squid.conf, i have added :
url_rewrite_program /usr/local/libexec/jesred

jesred.conf :
allow=/etc/jesred/redirector.acl
rules=/etc/jesred/redirector.rules

redirector.acl:
0.0.0.0/0

redirector.rules:
regex *.swf http://x.x.x.x/blocked.gif

Can you help me please
thank's