I have a similiar problem. However, the set of checkboxes I am trying to clear are contained within a variable set. This code does not seem to clear it. I've tried adding variable.variable name but that didn't work either. Here is my code at the moment:

function onChange(control, oldValue, newValue, isLoading, isTemplate) {  

if (isLoading ) {  

        return;  

}  

  if (newValue == false){  

      g_form.setValue(variables.PAY_Sage_305, '');  

  }  

  if(newValue == true){  

    // your code  

  }  

}

I have this set in a Catalog Client Script tied to a Catalog Item - referencing my Catalog and the variable name Payments. How it needs to work is we have separate variables for 4 groups - Payments, SBS, MMBS, Other. When one of these is clicked, it presents another group of checkboxes with options they can select. These latter are each contained within a variable set for that particular group. For instance - the Payments has a variable set called BRG PL Payments which contain the options associated with the Payments checkbox - PAY_Sage_305 is one of the variables within that variable set. If the user unselects the Payment checkbox after making selections within it, we want it to unselect those options, so if they were to check it again, PAY_Sage_305 would then be unchecked.