Queries :: Sum Fields From Two Tables In One Query

I have two tables:

Budget
Actuals

I have these fields in both tables:

MONTH, Organization Code, Account, SubAccount, AMOUNT

I want to Compare the results in a single query. However the amounts aren't correct and after a full day I cannot find the answer.

Code:
SELECT [Budget].Month AS [MONTH], [Budget].[Organization Code], [Budget].Account, Sum([Budget].AMOUNT) AS [Budget Amount], Sum([Actuals].AMOUNT) AS [Actuals Amount]
FROM [Budget], [Actuals]
GROUP BY [Budget].Month, [Budget].[Organization Code], [Budget].Account, [Budget].SubAccount
HAVING ((([Budget].SubAccount)="K08"));