function CountDown(){ var count = 1, infobox = document.getElementById("start"), atari = document.getElementsByTagName("div"), res = document.getElementById("result"), high = document.getElementById("high"), hit = Math.floor(Math.random()*6); function countdown(){ atari[hit].innerHTML = count; atari[hit].addEventListener("click",drop); } function drop(){ atari[hit].innerHTML = ""; atari[hit].removeEventListener("click",drop); count +=1; if(count<21){ random(); }else{ result(); } } function random(){ hit = Math.floor(Math.random()*6); countdown(); } function starts(){ start = performance.now(); infobox.removeEventListener("click",starts); countdown(); } function result(){ end = performance.now(); var time = (end-start)/1000; res.innerHTML = "記録:"+time+"秒"; if(time<10){ high.innerHTML = "Congratulations! 10秒切り達成!!"; } } infobox.addEventListener("click",starts); } document.addEventListener("DOMContentLoaded",CountDown);