Connection To SQL Server Database

I keep on getting an error when I try to connect to my database throuh my ASP.NET WEb application. The error says login failed for user...





Initially I was using Windows Authentication with Impersonation turned on. This let me connect to the database no problem.





However, I decided to change my method of connecting to the database for performance reasons but now I get this error.





I store my connection string in web.config and it looks like this:








<appSettings>


<add key="ConnectionString" value="server=server;


Database=dbname;Connect Timeout=15;Network Library=dbmssocn;uid=username;password=userpassword"/>


</appSettings>








Further down in the web.config file I still have this:








<authentication mode="Windows" />





<authorization>


<allow users="nameofusergroup" />


<deny users="?" />


</authorization>





<identity impersonate="true" />








Any ideas why I would be able to connect to the database using impersonation and not when I explicity give the crudentials in the connection string?





Regards





Wallace