How do I "Trigger once while true" individually

Ok, simple question. There is a Object, lets call it "Box", and I have some instances of this object.

When a boolean variable of the box change, I need there something happen with the box that have his variable changed.

I tryed

"|For each box            |

|Box Variable is true    | ------   Box Y set to 1000

|Trigger once while true |"

dont work, trigger once for the first instance and repeat infinite times for other objects.

"|Box Variable is true    | ------   Box Y set to 1000

|Trigger once while true |

dont work too, same effect above.

I had heard that the order of the conditions changes its effect, but I had tested for a long while and nothing happens. Tnx and sorry my english.

scirra.com/forum/trigger-once-and-instances_topic86899.html

Trigger once is a system command and it doesn't pick instances

I would go with Functions to solve this.

There is a place (or multiple places) in your events where you set this boolean to true. Instead of doing that, you should call a function that would set the boolean to true and then do your actions.

Example :capx

Actually I solve this problem with many ways, but I was curious about why "Trigger Once While True" was not working. Tnx Roccinio, forget about System Cond doesn't pick instances and Yes Guizmus, function solve all problems. Tnx all.

The correct way to use "trigger once while true" is to put it as a sub-event

(Sorry for being late of 16 months to reply ahahah)