How Excel can tell me i have entered a duplicate number

[Autofill]

how do i get excel to tell me i have entered a duplicate number in a specific
column

[Dav]

Well one way is to go to conditional formating and choose formula and in cell A1 put =countif(a:A,a1)>1 and format to turn the cells red

this will highlight duplicates in red

Regards

Dav

[Max]

"Autofill" wrote:
> how do i get excel to tell me
> i have entered a duplicate number in a specific column

Another play is to use Data Validation

Select col A
Click Data > Validation
Allow: Custom
Formula: =COUNTIF(A:A,A1)<2
Click OK

Test it out ..
--
Max
Singapore
http://savefile.com/projects/236895
xdemechanik
---