I'm trying to get YSlow to give me an A on the "Add Expires header" section by setting the web.config file.

I've been looking around and this is what I put in based on what's out there:

<staticContent>
    <clientCache httpExpires="15.00:00:00" cacheControlMode="UseExpires"/>
    </staticContent>
</system.webServer>

This is what I'm seeing in Firebug:

Response Headers

HTTP/1.1 200 OK
Server: ASP.NET Development Server/10.0.0.0
Date: Sun, 28 Aug 2011 13:54:50 GMT
X-AspNet-Version: 4.0.30319
Cache-Control: private
Content-Type: image/jpeg
Content-Length: 24255
Connection: Close


Request Headersview source
Host    localhost:50715
User-Agent  Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0) Gecko/20100101 Firefox/6.0
Accept  image/png,image/*;q=0.8,*/*;q=0.5
Accept-Language en-us,en;q=0.5
Accept-Encoding gzip, deflate
Accept-Charset  ISO-8859-1,utf-8;q=0.7,*;q=0.7
Connection  keep-alive
Referer http://localhost:50715/MySite/SiteHome.html
Pragma  no-cache
Cache-Control   no-cache

However, when I look at it in Firefox, Yslow is still giving an F on this, even after a Crtl-F5

What am I missing?

Thanks.

asp.net caching
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