Allen,

Thanks for the response.  I've done some homework on subqueries and I think
I'm on the right track.  I can now get the End Time populated for the lines
that are applicable and I've found a time comparision function that Microsoft
has made available, however, I'm having a problem getting the data to show up
in a report.  I think the problem I am having is due to the fact that I don't
have a value in every record for the EndTime.  I have set it up that way on
purpose because I don't want every time compared with the next time.  I've
tried to give an example below (for the sake of room, I've abbreviated Time
into "T").  

PID   Name          WorkCode   Time                          End T    
Elapsed T
------------------------------------------------------------------------------------
1      Pete Parse   Marketing   11/2/2007 7:55:12 AM    next T    ????
1      Pete Parse   Sales         11/2/2007 10:10:28 AM   next T    ????
1      Pete Parse   Log Out      11/2/2007 11:59:38 AM                ????
1      Pete Parse  Marketing    11/2/2007 1:01:23 PM     next T    ????
1      Pete Parse  Log Out       11/2/2007 5:10:45 PM                  ????

For instance, if someone logs out at lunch time, I don't want the time he is
on lunch to be counted toward the workday.  I have been able to successfully
get the data I want out of a subquery with specific criteria, and I've tested
the Microsoft function I'm using with a test Table, but I'm still getting an
error on my report when I try to put everything together -- "Invalid use of
Null."  I'm guessing it is because some of the "EndTimes" are null.  I have
tried a few things to get around this issue, but I'm not as familiar with
coding reports as I am forms, and each idea has been met with failure.  

Do you have any ideas of how I can get the information I'm looking for into
a report?

I just found out that every record in my EndTime field is blank.  I guess
this is where I should back up a little and explain a little about the course
I've taken.

I initially ran into the "Multi-level Group By not allowed" error when I
attempted to build my report off of the query I built the subquery in.  I
found the 4 suggested work-arounds on your (Allenbrowne.com/subquery-02.html)
website.  The first is not practical for me.  The second seemed like it would
logically work, however, when I unchecked the "show" box, the entire field
would disappear as soon as I closed the query.?!  Obviously, without the
field/subquery in existance, there is no way for me to use it in a
report...or anywhere for that matter (any idea why the field disappeared?).  
The language in the 3rd work-around didn't make sense to me -- it seemed like
it contradicted itself.  The 4th option sounded quite complex.  

So, I decided to try building a new query based on the query with my
subquery in it.  I included all the fields I needed in my report and switched
the record source from my original query to the new one and it opened without
an error.  I thought it was passing all the information I needed (since the
query itself displays all the data, including the subquery data), but as I
just found out by placing a text box in the report to display the EndTime, no
data is being passed to it from the new query.

So, I guess I'm back to trying to get around the "Multi-level Group By not
allowed" error.

Any help by anyone would be greatly appreciated.

Nathan