The phone icon in my (yahoo mesenger with voice) is not active, how can i activate it to make pc- to pc call?

Unfortunately, Yahoo! Messenger's voice and video will not work if you are behind a firewall. Check out this support page, which can help you configure your firewall/proxy server to allow voice and video connections:


http://help.yahoo.com/l/us/yahoo/messeng...

The phone icon in my (yahoo mesenger with voice) is not active, how can i activate it to make pc- to pc call?
you have just only have to mention id of ur buddy in call setup option but he should also have yahoo messenger with voice if still then it's not possible to call thn u can download new yahoo messenger wid beta voice