flagging non sequential numbering

[Kevin]

i log invoice numbers in a spreadsheet and i need to know when the next
number entered is not in sequential order so that no invoice get missed. How
do i go about setting excel up to catch and flag this. Please see example
below.

111567
111568
111570

i need it to flag the fact that 111569 did not get entered.

Please Help

 

[Bob Phillips]

Select A2:A100

Goto Format>Conditional Formatting

Change Condition 1 to Formula Is

add a formula of =A2<>A1+1

from the pattern tab, select a colour

OK out

 

[Kevin]

Thank you Bob,

That worked great, My boss is real happy now.

Thanks again for your help.

Kevin