I have this database structure:

GroupNumber  GN End Range    GroupName    CustServInd
7404            Don and Deb Lawyer          A
7405            Don and Deb Lawyer          A
7406            Don and Deb Lawyer           A
8683            Central Hardware Service   A
8684            Central Hardware Service   A
7616            Chemical Company HQ       A
9528            Wild Workout Center         A
0407            Wild Workout Center         A
8219            Wood Mill                  A
8764            Don and Deb Lawyer         A
   

TheGN End Range field is to be populated with the maximum GroupNumber for a
group, where a group is a unique GroupNumber and GroupName combo, AND THE
GroupNumber's are in SEQUENCE.  The Group Number End Range is only to be
filled when there is more than 1 GroupNumber for a group.  Thus, when the
module is complete, the above record set should look like this:

GroupNumber  GN End Range   GroupName                     CustServInd
7404            7406            Don and Deb Lawyer               A
8683            8684            Central Hardware Service        A
7616                   Chemical Company HQ            A
9528                   Wild Workout Center               A
0407                   Wild Workout Center               A
8219                   Wood Mill                    A
8764                   Don and Deb Lawyer              A

The query I have below fills in Group Number End Range for Don and Deb
Lawyer as 8764, but this is incorrect, as it is not in sequence.  Another
example would be Wild Workout Center.  My query groups them as one, with an
end range of 0407.  but they should be treated as separate groups, since the
numbers are not in sequence.

SELECT Min([GroupNumber]) AS MinGroupNumber,
IIf(Max([GroupNumber])>Min([GroupNumber]),Max([GroupNumber]),Null) AS
MaxGroupNumber, GroupName, CustSvcInd
FROM tblGroups
GROUP BY CustSvcInd, GroupName
ORDER BY CustSvcInd, Min(Groups.GroupNumber);

Hopefully this all makes sense!  I really need to take an sql class, I know
bits and pieces but that's it...