Transactions Within A Stored Procedure

Ive never used transactions before but i would like to start using them within stored procedures.

I have some questions about them and how roll backs function.

i have had a go a writing a basic procedure with a transaction

** updated {with Code wrap }


Code:

CREATE PROCEDURE TransferMoney
(
@Account1 Int,
@Account2 Int,
@myValue Numeric(18),
@myValue2 Numeric(18)
)
AS


-- STEP 1: Start the transaction

BEGIN TRANSACTION

-- STEP 2 & 3: Issue the Insert statement, checking @@ERROR after each statement

Insert Into Bank (Balance) Values (@MyValue)
WHERE AccountID = @Account1

-- Rollback the transaction if there were any errors

IF @@ERROR <> 0
BEGIN
-- Rollback the transaction
ROLLBACK
Return
END


Insert Into Bank (Balance) Values (@MyValue2)
WHERE AccountID = @Account2

-- Rollback the transaction if there were any errors

IF @@ERROR <> 0
BEGIN
-- Rollback the transaction
ROLLBACK
Return
END

-- STEP 4: If we reach this point, the commands completed successfully
-- Commit the transaction....

COMMIT




now have i used the
IF @@ERROR <> 0 correctly?


i want this transaction to only happen if the if both statement are true, stopping data insertion Errors when transfering from one account and adding to another.

any thoughts you have will be fantastic