no duplicate numbers

[Neuther]

I have 100 numbers (1-100) that are tickets. Since you really can't trust anyone i want to make something that won't let you use the same number twice. so if i use ticket number 57 and made copies then the next person to come up w/ ticket 57 when entered into the computer would get an error message. Also if possible i would like it to inprint the date and time when it moves it.

So i was thinking like cell a1 is empty and then you press enter (on say a button) it would move the number to a different part of the sheet and tag it w/ the date and time. i just can't get the macro to work that won't let me use the same nubmer twice.

Any ideas?

[BenjieLop]

I have 100 numbers (1-100) that are tickets. Since you really can't trust anyone i want to make something that won't let you use the same number twice. so if i use ticket number 57 and made copies then the next person to come up w/ ticket 57 when entered into the computer would get an error message. Also if possible i would like it to inprint the date and time when it moves it.

So i was thinking like cell a1 is empty and then you press enter (on say a button) it would move the number to a different part of the sheet and tag it w/ the date and time. i just can't get the macro to work that won't let me use the same nubmer twice.

Any ideas?

To prevent duplicate entries in a column

1. Select a range where entries will be made
(e.g., Cells A1:A100)
2. Go to Data/Validation/Custom
3. Enter this formula =countif($A$1:A100,A1)=1
4. Select "Error Alert" tab and enter any appropriate
message

Regards.