>>>I have a form using a bindingsource/bindingnavigator on a typed dataset.
>>>
>>>I have a BirthYear field and a DateofBirth field and a function to calculate the age based on those two values. I want to display the persons age on the form in a label or textbox.
>>>
>>>Where is a good place to call the function so that the Age is recalculated when either value changes or the person displayed changes?
>>
>>Is it Web App or Windows App?
>
>Windows (winforms).

Ok, then I don't know all events. We do have KeyPress, I assume, but are there any other events?

In Web form you would probably need to do this client-side.