Prevent two columns duplicate

[srizki]

I want to prevent duplicate entries in two columns combine, using data validation, i.e. say, column A has first name and Column B has last name, the first name can be duplicate, last name can be duplicate, but not both at the same time.

Thanks

 

[ISY]

Hallo

This is an example for a column
You could easily adapt to two columns

http://www.cpearson.com/excel/NoDupEntry.aspx

Otherwise, you can write code VBA

 

[srizki]

I think I will write a VBA.
THANKS