In my spreadsheet, Col A has a drop-down list with 5 choices. When "samples"
are selected from Col A, I want it to prevent the user from entering data in
Col C and D 9both date fields). The problem is, I don't want to put a formula
in there because then I would have to lock the cells and I need the
spreadsheet data entry area to remain unlocked for ease of deleting/inserting
etc. Additionally, I want the user to be able to free-key a date in Cols C
and D if they select anything other than "samples".

So, I am wondering if there is a formula that i can use for Conditional
Formatting so that if "samples" is selected in A, then C and D will fill with
black. that doesn't truly prevent anyone from typing but it gets the message
across that they shouldn't be typing in these fields because of their choice
in Col A. Is there a formula that could do this across Columns?
Thank you!