<!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">
function selectAll(){
var qx = document.getElementById("c");
var goods = document.getElementsByName("good");
if(qx.checked == true){
for(var i = 0;i<goods.length;i++){
goods[i].checked = true;
}
}else{
for(var i = 0;i<goods.length;i++){
goods[i].checked = false;
}
}
}
function check(){
var flag = true;
var qx = document.getElementById("c");
var goods = document.getElementsByName("good");
for(var i = 0;i<goods.length;i++){
if(goods[i].checked == false){
flag = false;
break;
}
}
if(flag){
qx.checked = true;
}else{
qx.checked = false;
}
}
</script>
</head>
<body>
<input type="checkbox" onclick="selectAll()" id="c">全选 全部商品<br>
<input type="checkbox" name="good" onclick="check()">鸡蛋<br>
<input type="checkbox" name="good" onclick="check()">鸭蛋<br>
<input type="checkbox" name="good" onclick="check()">鹅蛋<br>
</body>
</html>
原文：http://www.cnblogs.com/siashan/p/3920233.html