PHP+JS动态显示当前时间

<?phpheader("content-type:text/html;charset=gb2312");date_default_timezone_set("PRC");echo '<div id="time"></div><script type="text/javascript">var dayNames = new Array("星期日","星期一","星期二","星期三","星期四","星期五","星期六");function get_obj(time){return document.getElementById(time);}var ts='.(round(microtime(true)*1000)).';function getTime(){var t=new Date(ts);with(t){var _time=""+getFullYear()+"-" + (getMonth()+1)+"-"+getDate()+" " + (getHours()<10 ? "0" :"") + getHours() + ":" + (getMinutes()<10 ? "0" :"") + getMinutes() + ":" + (getSeconds()<10 ? "0" :"") + getSeconds() + " " + dayNames[t.getDay()];}get_obj("time").innerHTML=_time;setTimeout("getTime()",1000);ts+=1000;}getTime();</script>';?>

显示格式：2016-5-5 19:18:50 星期四