(Ask) Intranet Network Printing Trouble

[codexcool]

First.. i'm sorry 4 my english....

I have installed a network in a building.
There is 8 computer, 4 in the first floor and 4 in the 4th floor.
In the first floor, there is 1 computer that use as a gateway and internet server. and all is use win xp as OS.
In the fourth floor, there is 1 computer as intranet server with win2k based and asp based for the intranet. and the other (client pc) use win 98 as OS.
All ping is okey and all computer is connected one to another....
Printing job from office can work well. ( The printer is located in the first floor.
The problem is if they use the intranet web and want to print, there is a box display that we have to fill username and password to access the intranet server (in the 4th floor). I try to print from the client in the 4th floor and it works!!!
So i back to the first floor and try again to print, i try to fill all username and password that maybe work but its still can't print, and the same box is appeared.

Can anyone help why i can't print and have to fill username and password??