InfoPath Dev

I created a new thread last week and didn't receive any responses. I did some more research and maybe I can ask the question better now. I have an Access DB which contains my Leave Tracking data. The InfoPath form I am creating will be a leave request form with several fields being calculated for the user. I am allowing a user to enter a date ...

I use the following XPath script and get ''''my:WhenIfDate'' does not point to a valid location path of a field or group.'' I am trying to calculate only found records in a query. When I don't try and filter the math goes off without a hitch. sum(d:Sick_Trans/@UnitsReceived[d:Sick_Trans/@TransactionDate < ../../my:WhenIfDate])