We have A netopia router

we have this router and we connect to the internet using, now we have lost the user name and pasword to this router. there are many ways to login to the router and change the settings, like telnet or program consol. I could reset the router and justget in to it but then I have to get the ISP info and that will cost some money to get. since they are $$$ hungry people.
So if you know of any way to some how find the pass to this router please let me know.
THanks A LOT