<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
var count=document.mailfor.mail.length;
var ch=document.mailfor;
function allCheck(){
// var count=document.mailfor.mail.length;
// var ch=document.mailfor;
for(var i=0;i<count;i++)
{
ch.mail[i].checked=ch.allcheck.checked;
}
}
function allCancel(){
// var count=document.mailfor.mail.length;
// var ch=document.mailfor;
for(var i=0;i<count;i++)
{
if(ch.mail[i].checked==true)
ch.mail[i].checked=false;
}
}
function Fc(){
for(var i=0;i<count;i++)
{
ch.mail[i].checked=!ch.mail[i].checked;
}
}
</script>
</head>
<body><form name="mailfor">
<input type="checkbox" name="mail" value="1">邮箱1<br />
<input type="checkbox" name="mail" value="2">邮箱2<br />
<input type="checkbox" name="mail" value="3">邮箱3<br />
<input type="checkbox" name="mail" value="4">邮箱4<br />
<input type="checkbox" name="allcheck" onclick="allCheck()" >全选<br />
<input type="button" name="cancel" onclick="allCancel()" value="取消"><br />
<input type="button" name="fc" onclick="Fc()" value="反选"><br />
</form>
</body>
</html>我把注释的去掉就可以用，不过感觉不够简洁，设了全局变量之后，貌似用不了那些功能了！
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
var count=document.mailfor.mail.length;
var ch=document.mailfor;
function allCheck(){
// var count=document.mailfor.mail.length;
// var ch=document.mailfor;
for(var i=0;i<count;i++)
{
ch.mail[i].checked=ch.allcheck.checked;
}
}
function allCancel(){
// var count=document.mailfor.mail.length;
// var ch=document.mailfor;
for(var i=0;i<count;i++)
{
if(ch.mail[i].checked==true)
ch.mail[i].checked=false;
}
}
function Fc(){
for(var i=0;i<count;i++)
{
ch.mail[i].checked=!ch.mail[i].checked;
}
}
</script>
</head>
<body><form name="mailfor">
<input type="checkbox" name="mail" value="1">邮箱1<br />
<input type="checkbox" name="mail" value="2">邮箱2<br />
<input type="checkbox" name="mail" value="3">邮箱3<br />
<input type="checkbox" name="mail" value="4">邮箱4<br />
<input type="checkbox" name="allcheck" onclick="allCheck()" >全选<br />
<input type="button" name="cancel" onclick="allCancel()" value="取消"><br />
<input type="button" name="fc" onclick="Fc()" value="反选"><br />
</form>
</body>
</html>我把注释的去掉就可以用，不过感觉不够简洁，设了全局变量之后，貌似用不了那些功能了！
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
function fun(o){
var input=document.getElementsByName("mail");
for(var i= 0,l=input.length;i<l;i++){
if(o==""){
input[i].checked=!input[i].checked;
}else{
input[i].checked=o;
}
}
}
</script>
</head>
<body>
<form name="mailfor">
<input type="checkbox" name="mail" value="1">邮箱1<br />
<input type="checkbox" name="mail" value="2">邮箱2<br />
<input type="checkbox" name="mail" value="3">邮箱3<br />
<input type="checkbox" name="mail" value="4">邮箱4<br />
<input type="checkbox" name="allcheck" onclick="fun(true)" >全选<br />
<input type="button" name="cancel" onclick="fun(false)" value="取消"><br />
<input type="button" name="fc" onclick="fun('')" value="反选"><br />
</form>
</body>
</html>这样简单一点。