<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <script type="text/javascript">
        var id;
        function startInterval(){
            id = setInterval(function(){
                alert("interval evaling");
            },3000);
        }

        function testClear(){
            clearInterval(id);
        }

        function testCount(){
            var count = 0;
            var date;
            setInterval(function(){
                count++;
                //console.log(count);
                date = new Date();



                //document.getElementById("count").innerHTML = ""+count;
                document.getElementById("count").innerHTML = date.getFullYear()+"年"+(date.getMonth()+1)+"月"+date.getDate()+"日 "+date.getHours()+":"+date.getMinutes()+":"+date.getSeconds()+":"+date.getMilliseconds();
            },1)
        }

        /**
         *
         */

    </script>
</head>
<body>
<input type="button" onclick="startInterval()" value="interval"/>
<input type="button" onclick="testClear()" value="clear"/>
<input type="button" onclick="testCount()" value="count">
<div id="count" style="color: red;">
    0
</div>
</body>
</html>