Login failed for user 'username'. The user is not associated with a trusted SQL Server connection.

Hi Friends,

I have created a web project which will access a .net class library(dll) for database related activities.
That Sql server is located in remote location. We connect using Windows Authentication mode with that sql server.

Everything works fine when i run the web application from VS 2008. But after deploying in IIS 5.1, i am getting the following error.
"Login failed for user 'username'. The user is not associated with a trusted SQL Server connection."

i traced this error by creating a log file.

Please help me... ASAP...

Thanks in advance...

Regards,
Suresh