a/21800735/1636522

by wared

HTML

<button>click to play</button> <span></span>

CSS

*{font:normal 16px Arial}

JavaScript

var tid, span, button;
span = document.getElementsByTagName('span')[0];
button = document.getElementsByTagName('button')[0];
button.onclick = toggle;

function play(sec) {
    var i;
    span.innerHTML = sec + ' sec';
    if (sec) {
        tid = setTimeout(function () {
            play(--sec);
        }, 1000);
    } else {
        setTimeout(function () {
            i = 0;
            while (i++ < 5) alert('trapped :P');
            toggle();
        }, 0);
    }
}

function toggle() {
    if (tid) {
        clearTimeout(tid); // phew...
        tid = null;
        span.innerHTML = '';
        button.style.color = 'black';
        button.innerHTML = 'click to play';
    } else {
        play(5);
        button.style.color = 'red';
        button.innerHTML = 'DO NOT click me again!';
    }
}