Error Handling for Data Validation List

[mikeyank]

Help me, good people!

I have a excel document that is very heavy with Data Validation List Boxes. Below is just one example. Error handling is what I am trying to figure out.
Description:
I have 3 List Boxes.
One list box data is based on data selected in the previous list box.

1st List Box uses this formula: =Series
2nd List Box uses this formula: =INDIRECT($C$2)
3rd List Box uses this formula: =INDIRECT($C$3)

It all works! HOWEVER....
If user decides to go back and change selection in first or second list box, and forgets to change the data in the second or third box, then data will be incorrect. How do I solve this problem?
Is there anyway to write something so it would give them an error message and instructing them to correct the data?

Thanks

 

[tirnovali]

??is that already handled by trigger properties ???