<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<script>
window.onload = function(){
var aInput = document.getElementsByTagName('input');
var count = 0;
aInput[0].onclick = function(){
if(this.checked == true){
for(var i = 1; i < aInput.length; i++){
aInput[i].checked = true;
}
count = aInput.length - 1;
document.title = count;
}else{
for(var i = 1; i < aInput.length; i++){
aInput[i].checked = false;
}
count = 0;
document.title = count;
}
}
for(var i = 1; i < aInput.length; i++){
aInput[i].onclick = function(){
if(this.checked == true){
count++;
}else{
count--;
}
if(count == aInput.length -1){
aInput[0].checked = true;
}else{
aInput[0].checked = false;
}
document.title = count;
}
}
}
</script>
</head>
<body>
<input type="checkbox" />
<hr/>
<input type="checkbox" />
<input type="checkbox" />
<input type="checkbox" />
<input type="checkbox" />
<input type="checkbox" />
</body>
</html>