TRY...CATCH, ROLLBACK, COMMIT IN SQL SERVER 2008

TRY-CATCH

BEGIN TRY

INSERT INTO TAB1

SELECT 1,'AAA',10

UNION ALL

SELECT 2,'BBB',20

UNION ALL

SELECT 3,'CCC',30

UNION ALL

SELECT 4,'DDD',40

UNION ALL

SELECT 5,'EEE',50

END TRY

BEGIN CATCH

RAISERROR('ERROR: PLEASE VERIFY',16,1)  

END CATCH

ROLLBACK

BEGIN TRY

BEGIN TRAN TRN1

INSERT INTO TAB1

SELECT 1,'AAA',10

UNION ALL

SELECT 2,'BBB',20

UNION ALL

SELECT 3,'CCC',30

UNION ALL

SELECT 4,'DDD',40

UNION ALL

SELECT 5,'EEE',50

END TRY

BEGIN CATCH

ROLLBACK TRAN TRN1

END CATCH

COMMIT

BEGIN TRAN TRN1

INSERT INTO TAB1

SELECT 1,'AAA',10

UNION ALL

SELECT 2,'BBB',20

UNION ALL

SELECT 3,'CCC',30

UNION ALL

SELECT 4,'DDD',40

UNION ALL

SELECT 5,'EEE',50

COMMIT TRAN TRN1

ROLLBACK-COMMIT

BEGIN TRY

BEGIN TRAN TRN1

INSERT INTO TAB1

SELECT 1,'AAA',10

UNION ALL

SELECT 2,'BBB',20

UNION ALL

SELECT 3,'CCC',30

UNION ALL

SELECT 4,'DDD',40

UNION ALL

SELECT 5,'EEE',50

COMMIT TRAN TRN1

END TRY

BEGIN CATCH

ROLLBACK TRAN TRN1

END CATCH