Locking cell depending on outcome of formulae
 

Am hoping that someone has the answer to this. In cell B1 I have a formulae
=If(a1="additional concern","Add Conc","Please Select"). It also has a drop
down validation box with other values.
I want to be able to lock B1 if the outcome of the formulae is "Add Conc",
but leave it unlocked for users to select from the drop down if "Please
Select".
This spreadsheet will have additional rows inserted at various times, so
want this VBA to work for each row as it is inserted and data input.
Thanks in anticipation.