winxp, winxp firewall, and winvnc

[ThurzNite]

I'm trying to connect from my win2k machine to my other winxp machine in the next room. I'm using a linksys router. If the winxp machine has the firewall turned on, I can't connect (nor can I ping). When the firewall's off, I can connect and ping. How do I modify winxp's firewall to allow me to connect? I'm trying to use port 5875.
Thanx!
Jae