Hi newera,
i have followed your post.i have already aded in .htaccess and in httpd.conf, restarting and rebooting vps. but it still not show cache-control header. i get this result after apply this finally.
HTTP/1.1 200 OK
Date: Sat, 04 Jun 2011 05:39:28 GMT
Server: Apache
Set-Cookie: pass_hash=ymHNKVJE1EloJ_uMoYfDg-5ObZxRkKXJnysVhIF9KONnMsjeSRVmHqKSEgALiprF; expires=Tue, 07-Jun-2011 05:39:28 GMT; path=/; domain=; httponly
Set-Cookie: session_id=HRJAOXmVnSNBjSJsSWxZXKQRh_I2ZxBgUAOeYE6nOlbaIfrd6nHBU7d_lPqm8wfKfK; path=/; domain=; httponly
Cache-Control: no-cache,must-revalidate, max-age=0
Expires: Fri, 03 Jun 2011 05:39:29 GMT
Pragma: no-cache
Content-Encoding: gzip
Vary: Accept-Encoding
Keep-Alive: timeout=15, max=300
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: text/html;charset=UTF-8