实时显示当前时间php代码

<?php
header('content-type:text/html;charset=gbk');
date_default_timezone_set('PRC');
$n=chr(13);
echo "<SCRIPT LANGUAGE=\"JavaScript\">".$n;
echo "document.write('<div id=\"TimeShow\" align=\"right\" style=\"MARGIN-right:0px;font-size:9pt;font-family:宋体\">?</div>');".$n;
echo "var y=".date("Y")."; //年 ".$n;
echo "var m=".date("n")."; //月 ".$n;
echo "var d=".date("j")."; //日 ".$n;
echo "var w=".date("w")."; //星 ".$n;
echo "var h=".date("H")."; //时 ".$n;
echo "var i=".date("i")."; //分 ".$n;
echo "var s=".date("s")."; //秒 ".$n;
echo "var hstr=istr=sstr=a='';".$n;
echo "var ww = Array('日','一','二','三','四','五','六');".$n;
echo "function clock(){".$n;
echo " s++;".$n;
echo " if (s==60) {i+=1;s=0;}//秒进位".$n;
echo " if (i==60) {h+=1;i=0;}//分进位".$n;
echo " if (h==24) {w+=1;d+=1;h=0;}//时进位".$n;
echo " if (w==7) {w=0;}//星期进位".$n;
echo " if (m==2) { //是否是二月份？".$n;
echo " if (!y%4>0) { //不是闰月（二月有28天）".$n;
echo " if (d==30){".$n;
echo " m+=1;".$n;
echo " d=1;}".$n;
echo " }".$n;
echo " else { //是闰月（二月有29天）".$n;
echo " if (d==29){".$n;
echo " m+=1;".$n;
echo " d=1;}".$n;
echo " }".$n;
echo " }".$n;
echo " else { //非2月份的月份".$n;
echo " if (m==4 || m==6 || m==9 || m==11) { //只有30天的月份".$n;
echo " if (d==31) {".$n;
echo " m+=1;".$n;
echo " d=1;}".$n;
echo " }".$n;
echo " else { //有31天的月份".$n;
echo " if (d==32){".$n;
echo " m+=1;".$n;
echo " d=1;}".$n;
echo " }".$n;
echo " }".$n;
echo " if (m==13) {y+=1;m=1;}//月进位".$n;
echo " if (h < 10) {hstr=' 0'+h} else {hstr=' '+h};".$n;
echo " if (i < 10) {istr=':0'+i} else {istr=':'+i};".$n;
echo " if (s < 10) {sstr=':0'+s} else {sstr=':'+s};".$n;
echo " if (h < 13) {astr=' am';} else {astr=' pm';};".$n;
echo " TimeShow.innerHTML=y+'年'+m+'月'+d+'日 '+'<font color=#66FFFF>星期'+ww[w]+'</font>'+hstr+istr+sstr+astr;".$n;
echo " setTimeout('clock()',1000);".$n;
echo "}".$n;
echo "clock();".$n;
echo "</SCRIPT>".$n;
?>