MySQL Transactions

[Laeg]

Just a quick sample in MSSQL first to show my point.

BEGIN TRANSACTION

UPDATE tblFoo set a = 1

IF @@ERROR <> 0
	BEGIN
		RETURN 1
		ROLLBACK TRANSACTION
	END
ELSE
	BEGIN
		UPDATE tblBar set b = 2

		IF @@ERROR <> 0
			BEGIN
				RETURN 1
				ROLLBACK TRANSACTION
			END
		ELSE
			BEGIN
				RETURN 1
				COMMIT TRANSACTION
			END
	END

END

So in this instance @@ERROR catches ANY possible associated errors with the first
update statment, if any exist the statement is rolled back but if it is squeaky
clean then we head on to the next statement. How do I achieve this kind of
cascading block check in MySQL, I mean what is the equivalent of @@ERROR that
I can wrap in conditional statements?