Connect to internet with use of Proxy

Hi all,

I have a problem with connecting 2 the internet!
I use a Microsoft ISA server, i configured KnopPix 2 use that proxy, netconnections are OK couse i can ping it!

But when connecting 2 internet, it doesn't ask me for my username password... And that results in a errorpage from ISA that NO authentication credentials where supplied...


What am i doing wrong ??

Gr,
HM