Would like to open NAT but fell at first hurdle

[#1]

Hi
Would like to set my NAT to open -- have a Thomson router but when I connect to it it says ---
""The server 192.168.1.254:80 requires a username and password -- the Server says Thomson Gateway""

Cos I'm a bloke I threw all instruction books away on day 2 -- now 10 month later I can't remember these.. whats best / easiest way to find out
cheers
Gist

[#2]

Try here http://www.plus.net/support/broadband/hardware/thomson_advanced.shtml#routerLoginHelp

[#3]

cheers mate