IIS

Hi I am getting the following error after publishing my code . It works fine in a development server and is also working fine in my local machine but it is throwing the following error in production server.
System.ComponentModel.Win32Exception: Logon failure: unknown user name or bad password An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Win32Exception (0x80004005): Logon failure: unknown user name or bad password] [SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)] ...