javascript键盘事件全面控制脚本代码

<STYLE TYPE="text/css"> 
TD {text-align:center} 
</STYLE> 
<SCRIPT LANGUAGE="JavaScript"> 
function init() { 
    document.onkeydown = showKeyDown 
    document.onkeyup = showKeyUp 
    document.onkeypress = showKeyPress 
}

function showKeyDown(evt) { 
    evt = (evt) ? evt : window.event 
    document.getElementById("pressKeyCode").innerHTML = 0 
    document.getElementById("upKeyCode").innerHTML = 0 
    document.getElementById("pressCharCode").innerHTML = 0 
    document.getElementById("upCharCode").innerHTML = 0 
    restoreModifiers("") 
    restoreModifiers("Down") 
    restoreModifiers("Up") 
    document.getElementById("downKeyCode").innerHTML = evt.keyCode 
    if (evt.charCode) { 
        document.getElementById("downCharCode").innerHTML = evt.charCode 
    } 
    showModifiers("Down", evt) 
} 
function showKeyUp(evt) { 
    evt = (evt) ? evt : window.event 
    document.getElementById("upKeyCode").innerHTML = evt.keyCode 
    if (evt.charCode) { 
        document.getElementById("upCharCode").innerHTML = evt.charCode 
    } 
    showModifiers("Up", evt) 
    return false 
} 
function showKeyPress(evt) { 
    evt = (evt) ? evt : window.event 
    document.getElementById("pressKeyCode").innerHTML = evt.keyCode 
    if (evt.charCode) { 
        document.getElementById("pressCharCode").innerHTML = evt.charCode 
    } 
    showModifiers("", evt) 
    return false 
} 
function showModifiers(ext, evt) { 
    restoreModifiers(ext) 
    if (evt.shiftKey) { 
        document.getElementById("shift" + ext).style.backgroundColor = "#ff0000" 
    } 
    if (evt.ctrlKey) { 
        document.getElementById("ctrl" + ext).style.backgroundColor = "#00ff00" 
    } 
    if (evt.altKey) { 
        document.getElementById("alt" + ext).style.backgroundColor = "#0000ff" 
    } 
} 
function restoreModifiers(ext) { 
    document.getElementById("shift" + ext).style.backgroundColor = "#ffffff" 
    document.getElementById("ctrl" + ext).style.backgroundColor = "#ffffff" 
    document.getElementById("alt" + ext).style.backgroundColor = "#ffffff" 
} 
</SCRIPT> 
</HEAD>

<BODY onLoad="init()"> 
<H1>Keyboard Event Handler Lab</H1> 
<HR> 
<FORM> 
<TABLE BORDER=2 CELLPADDING=2> 
<TR><TH></TH><TH>onKeyDown</TH><TH>onKeyPress</TH><TH>onKeyUp</TH></TR> 
<TR><TH>Key Codes</TH> 
    <TD ID="downKeyCode">0</TD> 
    <TD ID="pressKeyCode">0</TD> 
    <TD ID="upKeyCode">0</TD> 
</TR> 
<TR><TH>Char Codes (IE5/Mac; NN6)</TH> 
    <TD ID="downCharCode">0</TD> 
    <TD ID="pressCharCode">0</TD> 
    <TD ID="upCharCode">0</TD> 
</TR> 
<TR><TH ROWSPAN=3>Modifier Keys</TH> 
    <TD><SPAN ID="shiftDown">Shift</SPAN></TD> 
    <TD><SPAN ID="shift">Shift</SPAN></TD> 
    <TD><SPAN ID="shiftUp">Shift</SPAN></TD> 
</TR> 
<TR> 
    <TD><SPAN ID="ctrlDown">Ctrl</SPAN></TD> 
    <TD><SPAN ID="ctrl">Ctrl</SPAN></TD> 
    <TD><SPAN ID="ctrlUp">Ctrl</SPAN></TD> 
</TR> 
<TR> 
    <TD><SPAN ID="altDown">Alt</SPAN></TD> 
    <TD><SPAN ID="alt">Alt</SPAN></TD> 
    <TD><SPAN ID="altUp">Alt</SPAN></TD> 
</TR> 
</TABLE> 
</FORM>

[Ctrl+A 全选注:如需引入外部Js需刷新才能执行]