Conditional Error Message

[wagstaffjh]

Essentially I want a cross between data validation and conditional formatting. When I manually update a data table, several columns contain cells with formulas to recalculate based on the updated information in the record. I want an error message to alert if a "#N/A" occurs in any of the cells in one of those calculating columns to alert the user since the formula's inability to calculate indicates some bad data has arose. Thoughts?

[shg]

In a convenient cell,

=IF(SUMPRODUCT(--ISERROR(A1:A10)), "your message here", "")