Select your range (I used A1:L99) on sheet1 and will compare them to the value
on sheet2 (same address)

data|Validation
formula is:
=A1=INDIRECT("sheet2!rc",FALSE)

(A1 has to be the activecell)
And make the error alert a warning (on that last tab in the data|validation
dialog)

You may want to use conditional formatting, too.

Select the range
format|conditional formatting
cell value is:
not equal to
=INDIRECT("sheet2!rc",FALSE)

Give it a nice pattern. As soon as there's a difference, it'll change colors.

Kristen wrote:

Is there a way to create some sort of masking sheet over a current data sheet
that, when I re-input data, can tell me if there is a discrepancy between the
two values. For example, on Data Sheet 1, I have the value 98765, and when
re-entering the data, I mistype 11234, Excel can notify me of that problem?

This is for the purposes of verifying numberic data that has been entered
into a speadsheet. Thanks!

--

Dave Peterson