Well, you made the task even more challenging by not giving us a clue as to
how you want any duplicates removed... the simplest would be to trade the
number being overwritten for the number the user is typing in... would that
be acceptable or did you have some other way in mind? Also... what cells are
your numbers in (or what cells are they allowed to be in? Do you have any
controls to prevent the user from typing in more than 30 numbers in your
column (that would create an impossible situation to handle other than
removing the entry immediately)? Do you have any control to stop the user
from typing in a number bigger than 30?

--
Rick (MVP - Excel)


"Rad" wrote in message
...
Hi,

I am looking for an advice on this challenging algorithm.

I have a column in ms excel sheet and has the numbers from 1 €“ 30, and I
need to use vba code to allow the user to be able to change a number at a
time. Then as soon as it is changed, the column numbers need the change
so
there is no duplicate numbers in the column. In other words, the column
numbers 1- 30 must have only a number of each.

Any advice will be appreciated.

Thank you,
Rad





I thought about swapping, but the number next to the changed number must
be
reduced by a number until the number that has been changed from is
reached.

For example:
Original Changed Changed Again
1 1 1
2 2 2
3 3 10
4 4 3
5 9 9
6 5 4
7 6 5
8 7 6
9 8 7
10 10 8