Conditional logic to look up cell entry

Meera

Hello,

In my task tracking sheet, I have a status column (dropdown with one of the values being completed) and Completion Date column that I need help with.

I want to be able to conditionally allow Status field to set to complete only if there is an entry in the completion date in the Completion date column. If the date is not filled, it should prompt for a date or give an error. How can I accomplish this?

Thanks,

Meera

Paul Newcome

Are you able to provide a screenshot for context?