输入密码检测大写是否锁定js实现代码

<div> 
<input class="text" name="passwd" id="loginPasswd" type="password" style="*display:block;" /> 
<div style="color:#F90;padding:2px; position:absolute; display:none;" id="capital">大写锁定已开启</div> 
<script type="text/javascript"><!-- 
(function(){ 
var inputPWD = document.getElementById('loginPasswd'); 
var capital = false; 
var capitalTip = { 
elem:document.getElementById('capital'), 
toggle:function(s){ 
var sy = this.elem.style; 
var d = sy.display; 
if(s){ 
sy.display = s; 
}else{ 
sy.display = d =='none' ? '' : 'none'; 
} 
} 
} 
var detectCapsLock = function(event){ 
if(capital){return}; 
var e = event||window.event; 
var keyCode = e.keyCode||e.which; // 按键的keyCode 
var isShift = e.shiftKey ||(keyCode == 16 ) || false ; // shift键是否按住 
if ( 
((keyCode >= 65 && keyCode <= 90 ) && !isShift) // Caps Lock 打开，且没有按住shift键 
|| ((keyCode >= 97 && keyCode <= 122 ) && isShift)// Caps Lock 打开，且按住shift键 
){capitalTip.toggle('block');capital=true} 
else{capitalTip.toggle('none');} 
} 
inputPWD.onkeypress = detectCapsLock; 
inputPWD.onkeyup=function(event){ 
var e = event||window.event; 
if(e.keyCode == 20 && capital){ 
capitalTip.toggle(); 
return false; 
} 
} 
})() 
// --></script> 
</div>