I have entered a UDF given to me in an earlier question and it works. But,
if cells are altered it does not update as normal formulas do? Here's what
i've entered:

Function IsRed(r As Range) As Integer
IsRed = 0
If r.Interior.ClorIndex = 3 Then
IsRed = 1
End If
End Function

Then in the cell i want the answer:

=IF(IsRed(A1)=1,"P","")

If a cell is red I want to record "P" If clear "", but i want it to change
from "" to "P" if the cell is coloured at a later date. Any Ideas?

Thanx
Becks