//pac proxy by merans

function FindProxyForURL(url, host) {
 
 if (isInNet(myIpAddress(), "172.16.100.16", "255.255.255.0"))
  return "PROXY 172.16.100.2:22";
  return "DIRECT";    
}

OR even

function FindProxyForURL(url, host)
{
      return "PROXY 172.16.100.2:22; DIRECT";
}