Fred,
Assumed the column is "F" and F1 has the heading.
select F2:F10000 (F2 should be the active cell)
FormatConditional Formatting
in the Conditional Formatting dialog box
change the "cell value is" to "formula is"
and type the following formula
=COUNTIF($F$2:$F$10000,$F2)1
click Format button and select red form the colour dropdown box
click OK, OK
Cecil
"Fred" wrote in message
...
Have a spreadsheet with a column for Social Security #.The
person entering the data sometimes repeats the information
(Eg. Social Security # ). Being this is a lengthly
spreadsheet, is it possible to enter a formular that would
change the color(pattern)if the number is repeated(Eg
Cells with the repeat numbers the digits would turn red)