Message box when updating a cell value

Hi all,

I am new to the world of VBA and macros and have been finding my way around looking at old posts but I am now trying to do something I can't find any advice on.

I have created a document that we use to pass job data back to our client with. This uses data from our workforce management system and then runs a macro to add conditional formatting for validation purposes. The data then has to have any errors updated manually. I would like to be able to log this for reporting to our field managers.

What I am looking for is when a cell has had its data changed for a message box to appear and ask "Has a manual update been made?" from this I would like a yes / no answer.

If no,

The message box can just disappear

If yes,

I would like another message box to say "please enter reason for manual update"

and for it then to take you to the manual update cell (column AS) and for this cell to be highlighted red until a value has been entered. I would also like it to record in column AU a time stamp of when the user clicked Yes and who the user was.

Sorry if I am being stupid and am missing an obvious way of doing this. Any help or advice would be greatly received.

Thanks,
Mat

post a sample file to make it easy for understanding your requirement...

Book1.xlsx

The message box need to appear if data is changed with columns W:AR

Hope this helps.