Hello all,

Is there any way in Excel if I want to do this:
I have a list of code that MUST NOT be entered by user(let's called this
'blacklist")
Objective is when user enter a code that is in the 'blacklist' then he got a
Warning otherwise, the code is OK. eg. the black list is 1,2,3,4,5. and when
he enter 3, the validation will look at the list and it will give a warning.
but when he enter 0 or other than in the list, then the code can be entered
Thanks