Checkbox Group, select a checkbox depending on another

[attachment=0]02-09-_2016_16-11-29.jpg[/attachment]Hi Forum,

i hope that you can understand my problem and there is a solution.
I have a form with a Checkbox Group with this options:
v1=Title1
v2=Title2
v3=Title3 (requires Title2)
v4=Title4 (requires Title1)
v5=Title5

My problem is, how can I implement the following case:
If the User selects Title4, the Checkbox "v1" should be automatically checked in this moment.
I've tried different configurations in the "Events" tab, but nothings works.
e.g.

Did you have any idea how I can realize my plan?

Thanks a lot,
Peter

Hi Peter,

You'd have to do this with custom JavaScript - ChronoForms has problems with handling events on CheckBox groups and I'm pretty sure that this is well beyond it's built-in abilities.

Bob