I am limited to Version 6 of Filemaker at work so maybe the answer to my question is to spend the money for an updated version but.... I am trying to use a portal to summarize data from a second database. I want to multiply a field called "yield" on each of the portal lines to summarize for a final total yield. . In effect I want to calculate Total Yield = Yield 1 * Yield 2* Yield3 * etc to get a final total yield. The stahdard summary fields available though are things like average and standard deviation and they do not multiply each line. As an alternative, I can do it with a Script but that requires me to use a trigger to initiate the calculations each time a new record is created. I don;t know how to automatically trigger a calculation. once a portal lookup is initiated. Any help would be appreciated.