Referencing fields in other records for calculations
I want to access the value of a field in another record of a table to use in a default value calculation. Is there any way to access the value of Record ID#(Field Name) in a calculation? Specifically, I want to access the the value of a field in the record having next lowest (or previously entered) unique ID number to use in a calculation [e.g., Field Value(N)=Field Value(N-1) + Another-Field Value(N)]. In EXCEL one can just click on the cell above the cell containing the formula to place the value of the designated cell in a calculation. How does one do this in Filemaker Pro calculations for default entry values.