create trigger ...

as

delete ab
 from accountbalance ab
  inner join deleted d
   on ab.id = d.id

ALTER PROC [dbo].[usp_UpdateAccountBalance] @AccountId INT, @Amount MONEY
AS

DECLARE @Count INT;
SELECT @Count = COUNT(*) FROM dbo.AccountBalance
WHERE AccountId = @AccountId;

IF (@Count = 0)
BEGIN
	INSERT INTO dbo.AccountBalance
	        ( AccountId ,
	          Balance
	        )
	VALUES  ( @AccountId ,
	          @Amount  -- Balance - money	         
	        )
END
ELSE
BEGIN
	UPDATE dbo.AccountBalance
	SET Balance = Balance + @Amount
	WHERE AccountId = @AccountId; 	        
END

ALTER TRIGGER [dbo].[tr_AccountBalance]
ON [dbo].[JournalEntryLine]
AFTER INSERT, UPDATE, DELETE
AS 
	SET NOCOUNT ON;
	DECLARE @Amount MONEY;
	DECLARE @AccountId INT;
	
	DECLARE @action CHAR(8)  
	IF COLUMNS_UPDATED() <> 0 -- delete or update?
	BEGIN     
	  IF EXISTS (SELECT * FROM deleted) -- updated cols + old rows means action=update       
		SET @action = 'UPDATE'     
	  ELSE
		SET @action = 'INSERT' -- updated columns and nothing deleted means action=insert
	END 
	ELSE -- delete     
	BEGIN
	  SET @action = 'DELETE'
	END
------------------------------------------------------------------------
	DECLARE @Debit MONEY, @Credit MONEY;
	
	IF (@action = 'INSERT')
	BEGIN
		SELECT @AccountId = AccountId FROM INSERTED;
		SELECT @Debit = Debit FROM INSERTED;
		SELECT @Credit = Credit FROM INSERTED;

		IF (@Debit > 0)
		BEGIN
			SET @Amount = @Debit;
		END
		ELSE
		BEGIN
			SET @Amount = -@Credit;
		END
	END
	ELSE IF (@action = 'DELETE')
	BEGIN
		SELECT @AccountId = AccountId FROM DELETED;
		SELECT @Debit = Debit FROM DELETED;
		SELECT @Credit = Credit FROM DELETED;

		IF (@Debit > 0)
		BEGIN
			SET @Amount = -@Debit;
		END
		ELSE
		BEGIN
			SET @Amount = -@Credit;
		END
	END
	ELSE IF (@action = 'UPDATE')
	BEGIN
		SELECT @AccountId = AccountId FROM INSERTED;
		SELECT @Debit = Debit FROM INSERTED;
		SELECT @Credit = Credit FROM INSERTED;
		
		DECLARE @DebitDeleted MONEY, @CreditDeleted MONEY;
		SELECT @DebitDeleted = Debit FROM DELETED;
		SELECT @CreditDeleted = Credit FROM DELETED;	

		SET @Debit = @Debit - @DebitDeleted;
		SET @Credit = @Credit - @CreditDeleted;
		SET @Amount = @Debit - @Credit;
	END	
	
	EXEC usp_UpdateAccountBalance @AccountId, @Amount;

	IF (@action = 'INSERT')
	BEGIN
		
		-- update existing balances
		UPDATE dbo.AccountBalance
		SET Balance = Balance + i.Debit - i.Credit
		FROM AccountBalance b, INSERTED i
		WHERE b.AccountId = i.AccountId;
		
		-- insert new balances
		INSERT INTO dbo.AccountBalance (AccountId, Balance )
		SELECT ins.AccountId, ins.Debit - ins.Credit AS Balance
		FROM INSERTED ins, (
			SELECT AccountId, Debit - Credit AS Balance
			FROM INSERTED
			WHERE AccountId NOT IN (
				SELECT b.AccountId FROM dbo.AccountBalance b
				INNER JOIN INSERTED i
				ON b.AccountId = i.AccountId
			) 
		) n
		WHERE ins.AccountId = n.AccountId
	END
	ELSE IF (@action = 'DELETE')
	BEGIN
		UPDATE dbo.AccountBalance
		SET Balance = Balance - d.Debit + d.Credit
		FROM AccountBalance b, DELETED d
		WHERE b.AccountId = d.AccountId;
	END
	ELSE IF (@action = 'UPDATE')
	BEGIN
		UPDATE dbo.AccountBalance
		SET Balance = Balance + i.Debit - d.Debit - i.Credit + d.Credit
		FROM AccountBalance b, INSERTED i, DELETED d
		WHERE b.AccountId = i.AccountId AND b.AccountId = d.AccountId;
	END