Jack,
You want the index of the WS that the UDF is on ?

Public Function GetMyIndex1(AnyRange As Range) As Long
GetMyIndex = AnyRange.Parent.Index
End Function
'Or
Public Function GetMyIndex2() As Long
GetMyIndex = Application.Caller.Parent.Index
End Function

Add error trapping.

NickHK

"Jack Clift" wrote in message
...
Tom,

Have spent a bit more time on this - neither my nor your solution is going
to work as it relies on the 'activesheet' and hence updates all sheets
with
this number, not each sheet to its own.

Any ideas? is there someway to use the 'Me' keyword to differentiate
between which instance is calling the function

"Tom Ogilvy" wrote:

Function NumberOfSheets() As Integer
Application.Volatile
NumberOfSheets = ActiveWorkbook.Worksheets.Count

End Function

if all you have in the workbook are worksheets

Function SheetNumber() As Integer
Application.Volatile
SheetNumber = Activesheet.Index
End function

this falls apart if you have none worksheets in the workbook.


Function SheetNumber() As Integer
Application.Volatile
if sheets.count = worksheets.count then
SheetNumber = Activesheet.Index
else
' your looping method
end if
End function

application.Volatile makes the function volatile. It gets recalculated
on
every calculate event that would normally include that cell.

--
Regards,
Tom Ogilvy


"Jack Clift" wrote:

This problem is in two parts (excel 2003);
1. I have written a small macro that calculates the number of sheets
in a
workbook (writen in a macro module):
Function NumberOfSheets() As Integer

NumberOfSheets = ActiveWorkbook.Worksheets.Count

End Function

and am using this function in a cell a worksheet using the following
notation:
"=NumberOfSheets()"

issue is that the worksheet will not 'recall' the function unless I
select
and modify the cell (or the like). How do I make this function update
dynamically per all other cell functions - or at least if a sheets is
deleted
or created?

2. Similar to the above I am wanting to write a macro than enumerates
each
sheet in order as they are presented in the workbook:
Function SheetNumber() As Integer
Dim WS As Worksheet
Dim i As Integer

Set WS = ActiveSheet

For i = 1 To NumberOfSheets
If WS.Name = ActiveWorkbook.Worksheets(i).Name Then
SheetNumber = i
Exit Function
End If
Next i

SheetNumber = -1
End Function

The 'for next' loop seems a pretty clumsy way to do this, but I can't
think
of a better alternative. Any ideas.

This function also needs to dynamically refresh so am hoping solution
above
is applicable to this.

Thanks

Jack Clift