<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script>
// window.console.log();
// var ret1=window.confirm();
// var ret2=window.alert();
// var ret3=window.prompt();
// console.log(ret1,ret2,ret3);
var ID;
function tm() {
date=new Date();
date=date.toLocaleString();
// window.console.log(date);
var ele=document.getElementById("tm");
ele.value=date;
}
function begin() {
if (ID==undefined) {
tm();
ID = setInterval(tm, 1000);
}
var ele1=document.getElementById("btn1");
ele1.disabled="disable";
var ele2=document.getElementById("btn2");
ele2.disabled="";
}
function fin() {
clearInterval(ID);
var ele1=document.getElementById("btn2");
ele1.disabled="disable";
var ele2=document.getElementById("btn1");
ele2.disabled="";
ID=undefined;
}
</script>
</head>
<body>
<div>
<input type="text" id="tm">
<button id="btn1" onclick="begin()">start</button>
<button id="btn2" onclick="fin()" disabled="disable">end</button>
</div>
</body>
</html>
