Enable Http Compression in IIS 7.5

I'm trying to enable HTTP compression to my web site, my server is running Windows 2008R2 and IIS 7.5.

I followed these steps:

1. installed static and dynamic compression through the Serve manager.
2. Enable both static and dynamic option under my web site (mySite-Compression).

In my web.config file I have included:

<urlCompression doDynamicCompression="true"  doStaticCompression="true"/> 

When I checked my page headers the page's are not compressed.

What am I doing wrong?