Need query to separate 2 entry types in a table field

Hi all Access 2002 XP - Windows 2000 SP4

I now have a field in a table that records both Checks and Debit Card
transactions. I would like to be able to sort the two types of transactions
to be displayed on a form, using a filter form.

I need to separate the two types of transactions; i.e., Check and DBT from
the same CheckDBT field. I've been working on this for a while, and trying
to use different criteria for the query, but, I'm not having any luck
separating the two transaction types to sort by and display as a separate
transaction on the record form. Do I need to use a separate query for each
transaction type using specific criteria? Or...is there a way I can set
criteria in the
existing query to do any 'either/or' from the filter form control?

I now have a control to enter a Check no and call it up in the record form,
and this does work fine. But, I also want to call up the debit card
transactions to review by date period, or all of them at once. I have a
control and command button created for this on the filter form, however, I
am not sure how, or where, the query or code should be entered to separate
the DBT entries from the Check Numbers that are in the same field.

Here is the SQL for the current query for the record form.

PARAMETERS [Forms]![frmCheckingRecFilter]![TxtDate1] DateTime,
[Forms]![frmCheckingRecFilter]![TxtDate2] DateTime;
SELECT T.BeginBal, T.CheckNo, T.TransactionDate, T.Transaction,
T.CheckDBTAmt, T.DepositAmt, T.TransactionType, T.Comment, (SELECT
SUM(Nz(DepositAmt, 0) - Nz(CheckDBTAmt, 0) + Nz(BeginBal,0))
FROM MyCheckRegister T1
WHERE T1.TransactionDate = T.TransactionDate) AS RunningBalance
FROM MyCheckRegister AS T
WHERE (((T.TransactionDate) Between
[Forms]![frmCheckingRecFilter]![TxtDate1] And
[Forms]![frmCheckingRecFilter]![TxtDate2])) OR
((([Forms]![frmCheckingRecFilter]![TxtDate1]) Is Null)) OR
((([Forms]![frmCheckingRecFilter]![TxtDate2]) Is Null))
ORDER BY T.CheckNo, T.TransactionDate;

I would truly appreciate any suggestions on the best course of action.
Query...or code for form controls?

Jan