Highlighting cell if content is duplicate

[excelstart]

Hi,

I am compiling a list with 3 columns and unlimited rows.

I need to avoid duplicate content by highlighting a cell in red if th
cell content is contained in any of the cells in its respectiv
column.

I have been trying with the if statement doing something like:

if:Ax=A1:Ax-1

I am not sure if the above synthax is correct, and how to highlight th
cell in red if the condition is true. Cell contents can be both number
and letters (spaces are allowed).

Can you help?

J

 

[Bob Phillips]

Using conditional formatting, try a formula of

=COUNTIF(A:A,A1)>1

--
HTH

Bob Phillips

(remove nothere from email address if mailing direct)

 

[excelstart]

The formula below gives an invalid loop, could you put me a bit more i
the right direction? Also do you know how to highlight the cell in re
background if the condition holds true?

J