How to only allow input in one cell if another cell has text?

[excelrookie321]

Hi there,

I have three columns:
A - Keep
B - Kill
C - Comments

I want to set up some conditions that the user cannot enter column A or B unless they've made a comment in column C.

How do I do this?

It should show a pop up box saying 'Please enter a comment'.

Thank you

[mcmahobt]

Data Validation under the Data tab in the ribbon can allow you to do this relatively easily.

[excelrookie321]

Thanks mcmahobt.

I'm a complete beginner. Would you please outline the steps?

Thanks

[mcmahobt]

Say your Keep,Kill, and Comments start in cells A1:C1.

Select cell A1. In Data Validation, select Settings, then for the Allow section, select Custom. In the formula bar, enter:

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Then be sure to deselect "Ignore Blank" next to the Custom dropdown box.

This will only allow values (unless manually overwritten) in A1 if C1 is not an empty cell. To apply to B1, just copy cell A1 and paste into B1.

You can also enter Error Alerts that prompt the user to input a comment into C1 upon an error.

[excelrookie321]

You're a genius.

Thank you.