Method DoUndo()
    If undo[10000] > 0 Then 'Only undo if there is something to actually undo
        ClickCell(undo[0], False)
        undo[10000] = undo[10000] - 1 'Undo 10000 is used for storing how many undos have been done
        For Local i = 0 To 9998
            undo[i] = undo[i + 1]
        Next
    EndIf
    End

    Method updateUndo(cellNumber)
    Local backwards = 10000
        For Local i = 1 To 9999
            backwards = backwards - 1
            undo[backwards] = undo[backwards - 1]
        Next
        undo[0] = cellNumber
        undo[10000] = undo[10000]+1
    End