Try triggering your code with cell change(Worksheet_Change(ByVal Target As Range)). Since you already have code modify it to check- if value entered is duplicate then, delete the value entered and show warning in message box.


On Monday, 6 January 2014 04:02:54 UTC+5:30, wrote:
I can write code to recognize duplicate data, but I can't figure out how

to stuff that code it into data validation where a list source is already defined.



Is there a way for the data validation facility to stop, not remove, duplicate entries which are obtained from a list?



Thanks for you help.



Excel 2010