set up participant: select / unselect

Hello

we need to add a buton to allow the user who receive a set up participant task to select or unselect all particpants.

It will be standard in windchill 10 but we are in windchill 9.1...

Does anyone already developed such request ?

We tried to put all particpants unselected by default but we couln't since they belong to the context team.

And the buton select/unselect would work for any scenario...

I hope someone already had such requirements and could share it.

Regards