connection problem

Dear sir,
i have a problem with my sql server database that every time logged in the database on
my web server as login system , the error has occured .
The ERROR is
microsoft ole db ms sql server not logged as localhost/i_userlocalhost , so why this problem occurs.
i am watitng for your response.
thanking you,
saquib qureshi

Give me an example of what your connection string looks like.