515E sharing 1 IP with multiple servers inside firewall

Hi there ,

I have the PIX 515E i have only 1 public IP address and I want to
share it with multiple server inside my private network. For example I
have 2 server 1 web at 192.168.1.10  and 1 mail server  at
192.168.1.20. I wish to have people who connect on my public IP  using
****t 80 to forward to  my web server at 192.168.1.10 on ****t 80 and
people who connect on my public IP using ****t 110 to forward to my
mail server at 192.168.1.20. How can this done in the PIX ?



thanks

c1