How to set limits in forms

[maratkz]

We have a database of a shop where customers can accumulate and use points to buy stuff. I've created the Order form to add new orders however struggle with one part where customers you input how many points a customer wants to redeem. We tried to use the conditional restriction that you can find in the Property sheet but it does not work...


The point is if there is a typo by an employee and the redeeming points are 100 and he/she inputs 1000 by mistakes how can we prevent this from happening? Please help

[orange]

Your logic should include something along these lines:

How many points does this Customer have "in the bank"? Let's call that PointsAvail
How many points does this Customer wish to redeem with this purchase? Let's call that PointsToRedeem

You need to ensure that PointsToRedeem are <= PointsAvail and
PointsToRedeem are <=PurchaseTotal.
You do the check after the data is entered, but before the transaction is completed and the Invoice/Bill is presented.

You could also have a confirmation message based on the PointsToRedeem number.

[maratkz]

Where do I input that? Is there any tricky slot? I do the same with data validation rule in the property sheet and it does not work...

[orange]

I would do it with vba. Have you researched form and control events?
There are various free youtube videos discussing events and vba. Here's one.

[Micron]

There's probably 4 or 5 events you might be inclined to use from some tutorial - especially if you don't read them through completely.
For this, you'd want to use BeforeUpdate on the control, not the form, and cancel the event if the code doesn't pass the test. We can help if need be, as long as we know the control name and the logic that needs to be applied as the test. You should give it a shot - good learning experience.