Connect to Network Volume

[winginstitute]

Hi
I am trying to connect to a computer on our network...
I can connect if I click on network in a finder window:
In my finder window:
So I click network and 4 items appear: the servers' icon, a folder called local, a folder called workgoup and a folder called berkeley. (the server icon shows only my computer, the workgroup folder is empty, the berkeley folder has our PC and the local folder shows all the mac computers on the network)
I can double click on any of the mac computers within the local folder and it will prompt me to enter my user name and password and then I can select which volume I want to mount.

However, if I try to connect by going to Go->connect to server and then I try to enter afp:// or even smb://
I can't connect to any mac computers..I can connect to the PC by entering smb://berkeley03...

I have a feeling that it may be a syntax error but...

Thanks
Jin