谢谢大家帮忙改进钢琴程序

用鼠标按有反应，但是用键盘按没有反应，谢谢高手指点！键盘为DFBJK
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<link href="all.css" rel="stylesheet" type="text/css" />
<script language="javascript" type="text/javascript">
function $(id){
   if(document.all)
     return document.all[id];
   else if(document.getElementById)
     return document.getElementById(id);
   else
     return null;     
}
function play(id){
$(id).style.backgroundColor = "#00CCFF"; switch(id){
case 'keyDo': $("pianoMusic").innerText += "Do "; break;
case 'keyRe': $("pianoMusic").innerText += "Re "; break;
case 'keyMi': $("pianoMusic").innerText += "Mi "; break;
case 'keySol': $("pianoMusic").innerText += "Sol ";break;
case 'keyLa': $("pianoMusic").innerText += "La "; break;
default:
break;
}}
function endPlay(id){
$(id).style.backgroundColor = "#FFFFFF";
}
var ns4 = document.layers;
var ns6 = document.getElementById && !document.all;
var ns = ns || ns6;
var ie = document.all;var keysetId = null;
function setKeyFocus(newKeysetId){
keysetId = newKeysetId;
switch(keysetId){
case "myWidget":
document.onkeydown = handleKeyDownForX;
document.onKeypress = handleKeyDownForX;
document.onkeyup = handleKeyUpForX;
break;
default:
document.onkeydown = null;
document.onkeypress = null;
document.onkeyup = null;
break;
}
return;
}
function keyCode(e){
if(!e) e = window.event; //IE Event Model

if(ie) //IE & Opera Browser
return e.keyCode;
else if(ns) //Mozilla Serial Browser
return e.which;
else
return null;
}function autoplay(){
play('keyDo');
timerHandler = setTimeout("play();",500);
play('keyRe');

play('keyMi');

function handleKeyDownForX(e){
   if(!e) e = window.event; // fix for IE

var code;
if(ie)
code = e.keyCode; 
else if(ns)
code = e.which;
else { alert("Unknown Browser."); return; }

switch(code){
case 37: play('keyDo'); break; // Up Arrow
case 38: play('keyRe'); break; // Down Arrow
case 39: play('keyMi'); break;  // Left Arrow
case 40: play('keySol'); break; // Right Arrow
case 107: play('keyLa'); break; // Right Arrow
default: window.status = "Please Press Right Keys"; break;
}
}
function handleKeyUpForX(e){
if(!e) e = window.event; // fix for IE

var code;
if(ie)
code = e.keyCode; 
else if(ns)
code = e.which;
else { alert("Unknown Browser."); return; }

switch(code){
case 37: endPlay('keyDo'); break; // Up Arrow
case 38: endPlay('keyRe'); break; // Down Arrow
case 39: endPlay('keyMi'); break;  // Left Arrow
case 40: endPlay('keySol'); break; // Right Arrow
case 107: endPlay('keyLa'); break; // Right Arrow
default: window.status = "Please Press Right Keys"; break;
}
}
function fangqiKeyFocus(newKeysetId){
keysetId = newKeysetId;
block.active = false;
}
}
</script>
</head>
<body>
<div class="miniframecontent" id="monipiano">
<div class="pianoBox">
<Div class="pianokey" id="keyDo" onmousedown="play('keyDo');" onmouseout="endPlay('keyDo');" >宮</Div>
<Div id="keyRe" class="pianokey"onmousedown="play('keyRe'); " onmouseout="endPlay('keyRe');">商</Div>
<Div id="keyMi" class="pianokey"onmousedown="play('keyMi'); " onmouseout="endPlay('keyMi');">角</Div>
<Div id="keySol" class="pianokey"onmousedown="play('keySol');" onmouseout="endPlay('keySol');">徵</Div>
<Div id="keyLa" class="pianokey"onmousedown="play('keyLa'); " onmouseout="endPlay('keyLa');">羽</Div>
<br />
</div>
<Br /><Br />
<a id="autoplayBtn" href="#" onclick="autoplay();return false;">開啓自動彈奏</a>
&nbsp;&nbsp;
<a href="#" id="setKeyFocus"onClick="setKeyFocus();return false;">獲取鍵盤焦點</a>
<a href="#" id="fangqiKeyFocus" onClick="fangqiKeyFocus();return false;">放棄鍵盤焦點</a>
<Br /><Br />
<div id="pianoMusic"></div>
</div>
</bod
></html>