pm am 12小时格式化

<div id="m_tiem">PM 14:26</div>

tiem('m_tiem');

//pm am 12小时格式化
function tiem(id) {
    var obj = window.document.getElementById(id);
    var date = new Date();
    var h = date.getHours();
    var mm = date.getMinutes();
    var str;
    if(h > 12){
        str = 'PM';
    }else {
        str = 'AM';
    }

    mm = mm < 10 ? "0" + mm : mm;

    obj.innerHTML = str +'  '+ h + ":" + mm
　　setTimeout("tiem('"+ id +"')",1000);
}