I have two columns of data and want to check for duplicate entries.  For example, Column A and B has the following data:
A   B
1   2
2   4
3   1
4   3

Is there a formula that would check Column A Row 1 against all of Column B data?  Then I would want the duplicated field highlighted in a different color.  Or is this only possible in a macro?

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Answer from Richard Rost:

You could use the DLOOKUP function in a third field. Something like:

X:DLOOKUP("B","TableName","B=" & A)

If the value exists it will return it. If not, you should get a NULL. I haven't tested it, but the theory is sound. :)

You can use the DLOOKUP function to look up a specific value from a table or query.

Please see the following FREE video tutorial on my web site for step-by-step instructions on how to use DLOOKUP:

http://599cd.com/tips/access/dlookup-function?key=BlFAlEx