Hey everyone: using Excel 2000.

I have a spreadsheet like such (each # is in a different cell), starting on
A1:

1 2 3 4
1 5 6 3
2 7 4 3
1 5 6 3
6 3 2 5
1 2 3 4

These numbers are entered in manually as new records. Notice that "1 2
3 4" and "1 5 6 3" have been entered twice. I am trying to stop that
from happening.

When people are entering a new record, I don't want them to enter a row of
numbers if it's already been entered once before. So is there a way
(thinking about Validation) to create a condition that says "look at this row
of cells as a whole" and see if that set of numbers (in that specific order)
has been entered anywhere above?

Hope that makes sense. Thanks for your help!
Joe