THIS QUESTION IS NOT AIMED AT FIELD VALIDATION, but to when to perform recalculations. In Fox 2.x I would create an old value, have it pick up the value in the input field in the when clause, and then compare it to the actual value in the valid clause. In VFP I am not quite sure when to do this. If I use the above methodology, should I move picking up the old value into the gotfocus and then check it against the new value in the lostfocus? [It is vitally important that whenever a value is changed a recalculation occur, but since recalculation is time consuming it should occur only when a value changes.] I originally thought that in VFP, I would be able to just compare the .value against whatever it is bound to in the valid clause but that does not seem to work consistently. By the way, when does the underlying value get changed? Is there an ironclad rule to this? This is such a seemingly simple thing but it is turning into something for me that is akin to getting foxpro to quit when it does not want to.