Flash CS6 Button Not Working Despite No Compiler/Output Errors - actionscript-3

Question

I'm using Flash CS6, AS3 to create buttons for my project. Below is my code:
Intro_btn.addEventListener(MouseEvent.MOUSE_DOWN, Intro_func);
function Intro_func(event:MouseEvent):void {
gotoAndStop("Intro");
}
No errors appear when I run it on the output and compiler panel, and the same happens when I run it through the debugger. Also, I have used the exact same code for five other buttons, and they have no problems working. Please can someone tell me what is wrong with my code???

Answer 1

I would need to know more info of your code and the type of buttons you're using, however I would try this steps:
1.- add a Button component from the component inspector, set its instance name, and add that same function to the Click event:
newButton.addEventListener(MouseEvent.CLICK, Intro_func);
function Intro_func(event:MouseEvent):void {
trace("function executed");
gotoAndStop("Intro");
}
2.- run your app and test if the action is executed with this new button. If this test pass, then your problem is your button.
check this on your button:
check the base class of the button (be sure its a MovieClip or a Button class)
check if your button is enabled/disabled.
check if your button or its children has mouseEnabled and mouseChildren set as
true.
check there is no other object on top of the button either in your artboard or added by code at runtime.
I finally would suggest you to set useHandCursor = true; this will replace your mouse pointer arrow to a hand when you move over your button (this is just to test that your button is actually interacting with mouse).
hope this helps.

Answer 2

sorry for the delay, But I've found your solution, It's easier than you thought: your frame is delayed.
your Intro_btn script is on frame 10, however in frame one you're telling it to go to frame 9 (the "Erhu" frame label) so the actions to setup the event listener are never being called.
Also keep in mind the following:
objects exists only in their frames life time, if you have an object from frame 5 to 10, it will only exist in there, so moving to a previous or later frame (e.g. frames 4 and 11) will internally delete the object in memory along with their asociated actions, in english:
you placed the button in frame 10 and added its MOUSE_DOWN listener however, if you go back to frame 0, since the button doesn't exists in this frame it will be deleted from memory along with its listeners, so if you go from frame 0 to any other frame different than 10, your button will never have its listeners associated.
So my suggestion:
1.- add your function into frame 0:
function Intro_func(event:MouseEvent):void {
trace("function executed");
gotoAndStop("Intro");
}
2.- create a new layer. In this layer add a keyframe at the same position where your Intro_btn is(frame 10), and fill the rest of the timeline of this layer with empty frames (no keyframes), finally in the same layer add in frame 10 your listener Intro_btn.addEventListener. this way, the action is available for every subsecuent frame from frame 10.
hope this solves your problem.