Checking for duplicate entries over multiple worksheets

[madbloke]

I have an excel file with multiple workbooks (month by month) which,
amongst other things, contains reference number and name (columns C &
D).

When entering these details, I'd like it to check across all previous
entries (and previous months) for an exact match, and if it finds one,
to pop up a messagebox asking if it's ok to enter a duplicate.

I was thinking along the lines of a VLOOKUP formula, but that would get
overwritten when entering the data, so I'm stumped.

Any ideas?

 

[Guest]

Consider moving this over to MS-Access and turn the workbooks into relational
tables. You can then set field level validation.

_ PJK _

 

[madbloke]

Not possible, unfortunately - I specifically need to do this in Excel.

Consider moving this over to MS-Access and turn the workbooks int
relational
tables. You can then set field level validation.

_ PJK _