building a web service

hi
i have build an web service using C# as my lang, i build that one with the data base connection of sqlserver7 ,
i am not connecting through the windows integrated security, i am connecting through a user name and a password

the problem come when i want to add an web reference to a web client application i am not able to get the web reference could anyone please telll what may be the problem

one of the problem is comming in the event log viewer as some
HRESULt failed, and other is not a valid user name and password,

but the connection if am testing it is succed and i able to display the tables in web service

thanking you
vamshi krishna