Transaction levels in SQL server

The following are the different transaction levels in SQL Server with their syntax to set them:

1. READ COMMITTED
Syntax : SET TRANSACTION ISOLATION LEVEL READ COMMITTED

2. READ UNCOMMITTED
Syntax : SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED

3. REPEATABLE READ
Syntax : SET TRANSACTION ISOLATION LEVEL REPEATABLE READ 

4. SERIALIZABLE
Syntax : SET TRANSACTION ISOLATION LEVEL SERIALIZABLE