Autofill a radio button using other radio buttons

Question

I would like a question on my form "Q24 Decrease Smoke" (set of "Yes"/"No" radio buttons) to auto fill with a response of "No" if the user selects "Not at all" to 3 other questions (also sets of radio buttons).  If the user selects any other response to any of these 3 questions, I want the user to be able to manually select either "Yes" or "No". This is the code that I've tried, under the Mouse Up event of the "No" radio button option for Q24:
var a = getField("Q20 Smoke Cig").value;
var b = getField("Q22 Smoke other forms").value;
var c = getField("Q23 chew/snuff").value;
if(a=="Not at all" && b=="Not at all" && c=="Not at all") event.value = "On";
I'm new to Javascript, so am not entirely sure I am on the right track or what might be wrong here. Any help would be greatly appreciated. Thanks!

Answer 1

Have you tried to the set the value to to "No"?
The "Mouse Up" action only works when there is a "Mouse Up" action for the field.
I would look at using the script in the 'On Blur" action for the 3 fields with adjustments for the fields as needed for the field where the script is used.