SQL Server Enterprise Manager does not let you change your database name once you create it. If you want to change your database name, you may have to manually run the following script to change it. First of all you have to login to SQL Server using osql command line utility. Once you are in, fire following commands to rename database.
ALTER DATABASE OldName SET SINGLE_USER WITH ROLLBACK IMMEDIATE GO sp_renamedb 'OldName', 'NewName' GO ALTER DATABASE NewName SET MULTI_USER GO