Local SQL Server 2008 "Login failed for user" error

I am using sqlserver 2008 and .net Framework 4.5
my connectionstring as below:

enter code here  <connectionStrings>
<add name="ConnectionString" connectionString="data source=(local); Database:bongah; User id=myusername; Password=my password"/>

but this error appear when try to access database

Login failed for user 'myusername'.
How can i fix this error!!!
please.

1 answer

Just to make sure...

Did you change user name and password to an existing SQL Server login?