Philip,

Before you spend your $70, and on the basis of the type of users you have,
try this approach first.

Private Sub Workbook_Open()
Const sEDName As String = "__ExpiryDate"
Const nEvalPeriod As Long = 30
Dim ExpiryDate As Date
Dim sDate As String

On Error Resume Next
ExpiryDate = Evaluate(ThisWorkbook.Names(sEDName).RefersTo)
On Error GoTo 0

If ExpiryDate = 0 Then
ThisWorkbook.Names.Add Name:=sEDName, _
RefersTo:=Date + nEvalPeriod
ThisWorkbook.Names(sEDName).Visible = False
ThisWorkbook.Save
Else
If ExpiryDate < Date Then
ThisWorkbook.Close savechanges:=False
End If
End If

End Sub

'This is workbook event code.
'To input this code, right click on the Excel icon on the worksheet
'(or next to the File menu if you maximise your workbooks),
'select View Code from the menu, and paste the code



--
HTH

Bob Phillips

(remove nothere from email address if mailing direct)

"Phil C" wrote in message
...
Bob .. and RBS

Thanks for your responses. The sort of people on the receiving end are not
the types with the time or inclination to crack software security systems,
however weak. This only needs to be 'token security' to fulfill its
purpose
(i.e. clearly demonstarte that it is not the release version).

AppsSentinel sounds like it would do the job (I don't want to invest much
time on this, as I may not get many more requests for an evaluation
copy!),
so may invest in the Lite version ($70) to find out..

Philip


"Bob Phillips" wrote in message
...
You can do various things, but all of them are pointless if faced by
someone
who intends to crack it as Excel security is laughably weak.

I haven't used it with VBA myself, but the author assures me that
http://www.thescarms.com/appsentinel/default.asp the functionality does
extend to VBA, but of course you need to buy it.

--
HTH

Bob Phillips

(remove nothere from email address if mailing direct)

"Phil C" wrote in message
...
Hi folks

I have produced a complex spreadsheet (medical application) that is
now
available for sale at a modest price. It contains some VBA, but not
much.
I
am not an expert, but have made extensive use of Excel's built-in
functions
for curve fitting, graph ploting etc. A colleague in another (UK)
hospital
has asked about an 'evaluation version'. Is there a standard way of
producing a spreadsheet that has all the basic functionality to allow
a
user
to decide whether it works properly etc, but with something key
missing
(that would prompt them to buy the full version!)?

Time-out after (say) 30 days. I seem to recall that this is not
straightforward
Somehow disable the sheet | print function?
Any other ideas?

I am using Excel 2003. My development machine still has Windows 2000,
but
most potential users will have XP.

Thanks for you help.

Philip