VNC GIVING ME TROUBLE WHEN I TRY TO ACCESS IT FROM SCHOOL

hi guys.. i have 2 computers at home with vnc and a DLINK router...

i can access vnc over my home network with password and everything..

but when i go to school and try to access vnc... i get errors.

can someone tell me what ports i need to forward to both my PC's??

what else do i need to do?

computer 1: 192.168.0.123
computer 2: 192.168.0.125

help

thax