In UserCP-->Editprofile,i t filled adsense id ,i found another box--channel ID. i donnot know what's the means.anybody can tell me !!
If you have Adsense running on three different sites, you can set up a channel ID for each site to see which sites are getting clicks or if you run a large site, you can use channel IDs to tell which area of your site is getting more Adsense clicks. Channel IDs are set up in your Adsense control panel area.
https://www.google.com/adsense/support/bin/answer.py?answer=9868 take a look at this - hope you find an asnwer