Unselecting checkbox not making answer disappear

Question

Hi all
I almost have this bit of code working how i want it too, but just have one query. i would just like to set it up so that if a user unchecks the checkbox the answer disappears, at the momment the answer does disappear if you check another checkbox, which is fine, but if a user unselects a checkbox, so there are no checkboxes selected then there should be no answer being shown.
Hope this makes sense and that someone can help
Thanks
See code below
checkBox1a.selected = false;
ans1 = 0;
var checkboxListener:Object = new Object();
checkboxListener.click = function(evt_obj:Object) {
if (evt_obj.target.selected) {
  //evt_obj.target.label = "Selected!";
  checkBox1b.selected = false;
  checkBox1c.selected = false;
  checkbox1d.selected = false;
  ans1 = 0;
  trace(ans1);
  txtOutput.text="No it's the wrong Answer!";
} else {
  //evt_obj.target.label = "Unselected!";
  ans1 = 0;
  trace(ans1);
checkBox1a.addEventListener("click", checkboxListener);
checkBox1b.selected = false;
ans1 = 0;
var checkboxListener:Object = new Object();
checkboxListener.click = function(evt_obj:Object) {
if (evt_obj.target.selected) {
  checkBox1a.selected = false;
  checkBox1c.selected = false;
  checkbox1d.selected = false;
  //evt_obj.target.label = "Selected!";
  ans1 = 1;
  trace(ans1);
  txtOutput.text="Brilliant You got the Right Answer!";
} else {
  //evt_obj.target.label = "Unselected!";
  ans1 = 0;
  trace(ans1);
checkBox1b.addEventListener("click", checkboxListener);

Answer 1

You are creating/duplicating code that won't work for you.  You can only have one listener by that variable name, and you can combine the listener functions into one... the following would replace all of your code.
checkBox1a.selected = false;
ans1 = 0;
var checkboxListener:Object = new Object();
checkboxListener.click = function(evt_obj:Object) {
if (evt_obj.target.selected) {
  checkBox1a.selected = false;
  checkBox1b.selected = false;
  checkBox1c.selected = false;
  checkBox1d.selected = false;
  evt_obj.target.selected = true;
  if(evt_obj.target != checkBox1b){
     txtOutput.text="No it's the wrong Answer!";
     ans1 = 0;
  } else {
     txtOutput.text="Brilliant You got the Right Answer!";  
     ans1 = 1;
} else {
  ans1 = 0;
// here is where you will do whatever you are calling "making answer disappear"
checkBox1a.addEventListener("click", checkboxListener);
checkBox1b.addEventListener("click", checkboxListener);
checkBox1c.addEventListener("click", checkboxListener);
checkBox1d.addEventListener("click", checkboxListener);