In my Firewall, how do I un-block ports 20-22 including UDP.

I need to open these ports so I can use ftp.

My O/S is Windows XP but Ive been instructed i must open my ports through my active Firewall which is ZoneAlarm.

Note that whenever I connect online I chose the public connection not the private connection.

This potentially means my Firewall setting is on high and my ports are closed.

Is there a way to manually open the ports in questions (add the ftp site eg. but still connect online using public connection.

Or if you select public connection all ports get closed again?

Please help, thank you.