Display msgbox on save

This I am sure is very simple but I can't figure it out.

I am wanting to check a cell for a value on save and display a msgbox stating that the cell is empty(if it is) and not allow the sheet to be saved at that point. Is that possible? If not on save then when another worksheet is clicked. Either way would work.

Any examples would be very helpful.

Thanks,

never mind I got it figured out. Thanks,

never mind I got it figured out. Thanks,

Well done :) Please feel free to post your solution for the benefit of other members who are searching for an answer to this in the future....!

Colin