I'm able to perform cell validation by providing a list of acceptable values. This provides the user with a dropdown to select a suitable value. This is great, but I need to extend it so that it is mandatory when the value in another cell is provided, but must be blank if the other cell is not populated. For example:
- Cell A1 can take any value, including blank
- When cell A1 is blank, cell B1 must be blank
- When cell A1 is not blank, cell B1 must be populated from its dropdown list
Is it possible to achieve this?