How to set checkbox value

Hello All,I am trying to set a checkbox’s value if another field in the form is changed

I have field A a radio button field and field B a checkbox field I want when the user selects “Sales” in field A field B value=“Yes”

thanks

Subject: How to set checkbox value

Field B must be under field A and can be defined as a computed field.

@If(A=“Sales”;B=“Yes”;@Failur(“Need a choice for A”);

Regards