Actually, I think Data Validation may be exactly right for your situation...

Select the cells

From the Excel main menu:
<data<validation
<settings tab
Allow: Custom
Formula: 10^99

<error alert tab
Style: Warning
Title: Please Verify
Error message: OK to change the value?

With that method, the error alert will display for virtually all entries,
but since the style is Warning...it will allow the new entry.

Is that something you can work with?

***********
Regards,
Ron

XL2002, WinXP


"Phil" wrote:

Before a user changes data in a cell I want a text to opening asking if they
are sure they want to change the data. How do I go about this? The data can
be variable so validation won't cover it.