Jquery suddenly not working correctly

What code specifically is broken?

It is this variable that is broken: respcor

I code the responses and save them to respcor in this part:

if (code == 97 || code == 108 || code == 65 || code == 76) {
		if(listen == false) return;
	  	if (newword.type == "irrelevant" && code == 97 || newword.type == "irrelevant" && code == 65) {
	  		$("#false").fadeIn(50).delay(200).fadeOut(50);
			respcor = 0; cor.push(respcor);
	  	}
		if (newword.type == "irrelevant" && code == 108 || newword.type == "irrelevant" && code == 76) {
	  		//$("#false").fadeIn(50).delay(200).fadeOut(50);
			respcor = 1; cor.push(respcor);
	  	}
		if (newword.type == "target" && code == 97 || newword.type == "target" && code == 65) {
	  		//$("#false").fadeIn(50).delay(200).fadeOut(50);
			respcor = 1; cor.push(respcor);
	  	}
		if (newword.type == "target" && code == 108 || newword.type == "target" && code == 76) {
	  		$("#false").fadeIn(50).delay(200).fadeOut(50);
			respcor = 0; cor.push(respcor);
	  	}
		if (newword.type == "probe" && code == 97 || newword.type == "probe" && code == 65) {
	  		$("#false").fadeIn(50).delay(200).fadeOut(50);
			respcor = 0; cor.push(respcor);
	  	}
		if (newword.type == "probe" && code == 108 || newword.type == "probe" && code == 76) {
	  		//$("#false").fadeIn(50).delay(200).fadeOut(50);
			respcor = 1; cor.push(respcor);
	  	}

I don’t understand, that code is not on the page you linked.

If you click on Next the task starts. Sorry I didn’t mention that.

Put alert('dsadsa') within your If statements to see where it’s breaking

I did that. It worked without a problem. And exactly that is the problem: It stops coding the responses correctly all of the sudden. If it were for each user or irregularly I would be very confident that it is in the code, but it appears to stop working altogether for all users at a random moment.

As though $listen is never being set true?

$("#stimuli").text(newword.stim).fadeIn(10, function () {
    t1 = now();
    listen = true;
});

It’s rubbish that this only seems to occur randomly, but I fear that unless you can reproduce the problem then you cannot attempt to debug what’s causing it.

Yes. Are there any issues known where some javascript/jquery stopped working correctly after some time?
So what could have happen that made I go wrong so suddenly?
I will clean up my code now and several test versions again. I also contacted my webhost (bluehost) about that.

No there are no known issues with JavaScript, or JavaScript timing out – Talking about JavaScript itself rather than implementations of it.

There’s nothing relating to WordPress either as your program is running as a stand-alone application in the uploads folder. It is not using WordPress.