I currently use my db to record responses from patients taking part in research projects. i often ask questions about medical history and patients can either tellme that they had a particular treatment either when they were X years old orthey may give the year of the treatment. i wantt o have two fielsd one iwth age and one with year so either piece of information can be enetered and the other one is auto calculated useing DOB. I can get it to calculate age from year, but then it wont allow me to overide it and enter a n age without the year...can anone help

Age -> Case( Get(ActiveFieldName) = "YearTreatment" ; YearTreatment - Year(dob); Age )

YearTreatment -> Case( Get(ActiveFieldName) = "Age"; Year(dob) + Age; YearTreatment )

Both fields are numbers with their auto-entered calculation and 'Do not replace existing value for field' deselected.