What are you doing this on, a form or report? If this is a report, the
easiest answer may be to use the report's built-in running sum capabilities.
To get it to reset on each CUSIP, you would group on CUSIP then set a
textbox's Running Sum property to Over Group. Set the Control Source of the
textbox to the CUSIP field and the textbox will automatically give you a
running sum that resets for each CUSIP.

--
Wayne Morgan
MS Access MVP


"DMG" wrote in message
...
I have reviewed many of the posts on this board and I am still having an
issue with Dsum.
I have a table that contains ID(autonumber),CUSIP,Memo,Shares
For each Cusip there may be multiple records.
I need to keep a running total of the shares for each cusip.
I get the running total to work but I am having difficulty getting it to
reset at each new cusip.
This is relatively easy in Excel but I have too much data for Excel to
handle.
Please help!