如何实现当秒数不足10秒时显示格式为：01,02,03.....59
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>定时器</title>
<script type="text/javascript">
var attime;
var colorHead,colorFoot;
function clock(){
var time=new Date();
var HH = time.getHours();
if(HH<10){HH="0"+HH};
var MM = time.getMinutes();
if(MM<10){MM="0"+MM};
var SS = time.getSeconds();
if(SS<10){SS="0"+SS};
var ww = ["星期日","星期一","星期二","星期三","星期四","星期五","星期六"]
var nWeek = time.getDay();
attime= HH+":"+MM+":"+SS+" "+ww[nWeek];
document.getElementById("clock").value = attime;
}
var timer = setInterval(clock,1000);
</script>
</head>
<body>
<form>
<input type="text" id="clock" size="50" />
</form>
</body>
</html>