I am trying to set up a macro that automatically changes the background
colour of cells based on a condition. I have found the required macro with
the subseuqent conditional formatting requirements, and I can't get it to run
on a protected worksheet. It works fine when I unprotect the sheet, although
there are a number of formulas that I don't want users modifying.

The code is as follows:

Option Explicit

Dim NextTime As Date
Sub RepeatOneSec()
ActiveWorkbook.Styles("normal").NumberFormat = _
ActiveWorkbook.Styles("normal").NumberFormat
NextTime = Now() + TimeSerial(0, 0, 1)
Application.OnTime NextTime, "RepeatOneSec"
End Sub

Sub EndProcess()
Application.OnTime NextTime, "RepeatOneSec", , False
End Sub

The area I have problems with is the ActiveWorkbook.Styles lines. I get the
message "unable to set the NumberFormat property of the Style class"

Does anyone have any suggestions as to how to fix this?

Thanks
--
J