How To Remove DUPLICATES

I would like to remove duplicates from the following query. I would like it to display only one record depending on the InvoiceID. So only show one unique record based on Invoices.InvoiceID. Thanks!

SELECT DISTINCT Invoices.InvoiceID, Invoices.CustomerID, InvoiceDetails.InvoiceDetailID, Invoices.InvoiceDate
FROM InvoiceDetails INNER JOIN Invoices ON InvoiceDetails.InvoiceID = Invoices.InvoiceID
WHERE (((Invoices.InvoiceDate) Between #8/1/2004# And #8/31/2004#) AND ((InvoiceDetails.DeliverBy)=0))
ORDER BY Invoices.InvoiceID;