Javascript not working in swf output

Question

I am working on a project where the quiz requirements are quite unique and not all that logical, but it's what the client requires...
I have a lot of courses ("lessons") for this project. I'm using a fully custom quiz for each lesson. Because of the sheer number of courses, and the unique requirements, I am trying to leverage javascript for this project as much as possible.
I must publish both HTML5 and Flash versions. While not contractually required to publish a swf version, I am pretty certain that having both formats available will avoid having to deal with all of the browser issues down the road (already seeing issues in IE 11 on the client's PC).
So for each quiz question slide I have smartshapes which are acting as clickable text captions, like this:
Question text....
A. Answer choice a
B. Answer choice b
C. Answer choice c
D. Answer choice d
Each of the above answer choices is a smartshape button that is set to 'Execute Javascript' on click. In the javascript panel for each I have the following:
CORRECT_ANSWER = 'q1b';
ANSWER_CHOICE = (event.target) ? event.target.id : event.srcElement.id;
evaluate_answer(ANSWER_CHOICE, CORRECT_ANSWER);
In an external 'quiz.js' file I have the evaluate_answer function, which looks like this:
*********** quiz.js *************
var evaluate_answer = function (answerChoice, correctAnswer) {
  var answerChoice = window.cpAPIInterface.getVariableValue("ANSWER_CHOICE");
  var correctAnswer = window.cpAPIInterface.getVariableValue("CORRECT_ANSWER");
  if (answerChoice == correctAnswer) {
   cp.show('fb_q1_correct');
   cp.show('fb_q1_correct_next');
   cp.show('q1_answer_disabler');
  } else {
   cp.show('fb_q1_incorrect');
   cp.show('fb_q1_incorrect_next');
   cp.show('fb_q1_incorrect_remediate');
   cp.show('q1_answer_disabler');
*********** END quiz.js *************
The above works great in HTML5 output but not in the swf version. It looks like the swf version can't handle/pass the event.target, but that's just a guess.
Any ideas?

Answer 1

Hey again all,
The specific code importing the username isn't actually all that important, it's more of test to make sure that Javascript will actually work. I have a lot more code that needs to be processed as well, I'm using this as an example before I tackle the actual interworkings of the script. Therefore, I can't use a workaround, such as a system variable in the hyperlink, to pass the username.
I've now tried countless variations of methods of trying to run the JavaScript so far, including the ways that all of you have recommended. The only way the script will run is by my saving the file as a .htm and including an alert within the script in either the .htm file or in the .js file and calling from within the .htm. I haven't been able to get the process to run at all by including as an On Enter page action or as a .swf or by excluding the alert().  Can any of you get a Captivate 8 project with JavaScript to work as .swf alone on your server? Why does that alert have to before the setVariable in order for it to work in htm? I've changed the global security for Flash; is there another setting that I'm maybe missing?
Thank you all again for help. I'm completely stumped by this one!