Select the whole column (say it's col A), use Format/Conditional Formatting,
change "Cell Value Is" to "Formula Is", enter this formula:
=COUNTIF($A$1:$A$1000,A1)1
click Format, then Patterns tab, then select the red font.
HTH
Bob Umlas
Excel MVP


"trvlpal" wrote in message
...
I create a column and when i put a phone number in I want to have it
indivcate if its a duplicate perferrable in red