[squid-users] Gzip Supporting

Hello everyone,
I'm using squid 3.0 stable 16 as a accelerator for my IIS 7.0 server.
And I find that squid does not enable gzip for compressing, which
increases a lot of internet traffic. I can't find any option with which
I can enable gzip. Can anyone help me?
I attached the request and response headers below:

request header:
>Host *.*.*.*
>User-Agent Mozilla/5.0 (X11; U; Linux x86_64; zh-CN; rv:1.9.1.5)
Gecko/20091105 Fedora/3.5.5-1.fc11 Firefox/3.5.5 GTB5
>Accept text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
>Accept-Language zh-cn,zh;q=0.5
>Accept-Encoding gzip,deflate
>Accept-Charset GB2312,utf-8;q=0.7,*;q=0.7
>Keep-Alive 300
>Connection keep-alive
>Cookie ***
>If-Modified-Since Thu, 19 Nov 2009 03:41:39 GMT
>Cache-Control max-age=0

response from squid:
>Cache-Control public, max-age=1
>Content-Type text/html; charset=utf-8
>Expires Thu, 19 Nov 2009 03:43:39 GMT
>Last-Modified Thu, 19 Nov 2009 03:41:39 GMT
>Server Microsoft-IIS/7.0
>X-AspNet-Version 2.0.50727
>Date Thu, 19 Nov 2009 03:43:37 GMT
>Content-Length 249662
>X-Cache HIT from www.dealextreme.com
>X-Cache-Lookup HIT from www.dealextreme.com:80
>Via 1.0 www.dealextreme.com (squid/3.0.STABLE16)
>Age 9

response header from IIS7 if requested IIS server directly:
>Cache-Control public, max-age=0
>Content-Type text/html; charset=utf-8
>Content-Encoding gzip
>Expires Thu, 19 Nov 2009 03:37:38 GMT
>Last-Modified Thu, 19 Nov 2009 03:35:38 GMT
>Vary Accept-Encoding
>Server Microsoft-IIS/7.0
>X-AspNet-Version 2.0.50727
>Date Thu, 19 Nov 2009 03:37:38 GMT
>Content-Length 29707

-- 
Regards,
YX