Highlight cell that was changed (from NOT empty value)

Hi, all

Is it possible to program excell sheet that if I changed some value in cell from initial value to another it will be highlited. I work on food order sheet for one non profit, so we trying to make it work.
It should only work after initial value has been entered, not when initial value entered into Empty cell.
There also some vb macro already in this workbook, hope it will work well with them.

Generally I trying to emprove existing order sheet with all details for food delivery for one non profit. The only thing they have is MS donated Office 2007, so I'm trying to do my best of it. In this sheet we trying to track any order change so our drivers will see it clearly.


THanks to all for help.