效果：
代码：
<head runat="server">
<title></title>
<script type="text/javascript">
window.onload = function () {
var ckall = document.getElementById('ck1');
var ck = document.getElementsByName('name1');
ckall.onclick = function () {
for (var i = 0; i < ck.length; i++) {
if (ckall.checked == true) {
ck[i].checked = true;
}
else {
ck[i].checked = false;
}
}
}
};
</script>
</head>
<body>
<form id="form1" runat="server">
<input type="checkbox" id="ck1" />
全选
<div id="div1">
<input type="checkbox" name="name1" />
<input type="checkbox" name="name1" />
<input type="checkbox" name="name1" />
<input type="checkbox" name="name1" />
<input type="checkbox" name="name1" />
<input type="checkbox" name="name1" />
</div>
</form>
</body>