I would like to have a text field appear in either a group footer or report footer, but only if a particular field which is in the Details section has a particular value.  This is for an invoice, so if a customer has bought a particular item, that item will, of course, appear in the Details section.  I want this new associated text field to appear at the end of the report, after all of the other items that the customer bought are listed.  Can this be done?  If so, how?