EXTJS4.2 时间动态刷新显示

function clockGo() {
    Ext.TaskManager.start({
        run: function () {
            //Ext.getCmp("clock").setText(Ext.Date.format(new Date(), 'g:i:s A'));
            var showtime = document.getElementById("time");
            var now = new Date();
            var date = now.toLocaleString();// //获取日期与时间 如 2014年6月25日 下午4:45:06
            var hours = now.getHours();
            var minutes = now.getMinutes();
            var seconds = now.getSeconds();
            if (hours < 10) hours = "0" + hours;
            if (minutes < 10) minutes = "0" + minutes;
            if (seconds < 10) seconds = "0" + seconds;
            //var timestr = hours + ":" + minutes + ":" + seconds;
            var timestr = date ;
            showtime.innerHTML = timestr;
        },
        interval: 1000//每秒刷新一次
    });
}

//顶部面板
var north = new Ext.Panel({
    frame: true,
    plain: true,
    height: 56,
    border: false,
    region: 'north',
    items: [{
        baseCls: 'x-plain',
        border: false,
        height: 56,
        html: " <TABLE cellSpacing=0 cellPadding=0 width=100% background='/images/header_bg.jpg' border=0> <TR height=56><TD width=260><IMG height=56 src='/images/header_left.jpg' width=260></TD><TD style='FONT-WEIGHT: bold; COLOR: #fff; PADDING-TOP: 20px' align=right>当前时间：<span id=time></span>&nbsp;&nbsp;</div>当前用户：admin &nbsp;&nbsp; <A style='COLOR: #fff' href=''>修改口令</A> &nbsp;&nbsp; <A style='COLOR: #fff' onclick='if (confirm('确定要退出吗？')) return true; else return false;' href='' target=_top>退出系统</A> </TD><TD align=right width=268><IMG height=56 src='/images/header_right.jpg' width=268></TD></TR></TABLE><TABLE cellSpacing=0 cellPadding=0 width=100% border=0><TR bgColor=#1c5db6 height=4><TD></TD></TR></TABLE>"
    }],
    listeners: {
        'render': function () {
            clockGo();
        }
    }
});