control value instance combobox

[noos76]

hello

I have a combobox with item 20

with addInstance (1), etc.

until now everything function ok

my problem is to check the value of an instance??

what I mean if I choose the first item, and in the instance that I created, I select the first item again, I should have a message that tells me that I can not choose this option, you know how can I do??

[noos76]

anyone??