SQL Server - Setup - enable/disable SNAPSHOT isolation level

Environment:
1. SQL Server 2008

Background:
I need a script which would change isolation level to SNAPSHOT on current database. I tried to use CURRENT to make it work without much success. Instead used DB_NAME() built-in function to get the current database name and executed alter command as run time query.

Script snippet:

DECLARE @dbName VARCHAR(100) = '';
SELECT @dbName=DB_NAME();
IF ISNULL(@dbName, '') <> ''
BEGIN
DECLARE @cmd NVARCHAR(100) = 'ALTER DATABASE '+@dbName+'  SET ALLOW_SNAPSHOT_ISOLATION ON';
EXECUTE sp_executesql @cmd;
END;
GO


Helpful commands:

To enable:
ALTER DATABASE ABC SET ALLOW_SNAPSHOT_ISOLATION ON;

To disable:
ALTER DATABASE ABC SET ALLOW_SNAPSHOT_ISOLATION OFF;

How to check database isolation settings:
SELECT name
        , s.snapshot_isolation_state
        , snapshot_isolation_state_desc
        , is_read_committed_snapshot_on
        , recovery_model
        , recovery_model_desc
        , collation_name

FROM sys.databases s