全选框的操作
<!DOCTYPE html>
<html>
<head>
<title>全选</title>
<style type="text/css">
.box{
width:120px;
height: 250px;
border: 1px solid #000;
border-radius: 5px;
padding: 0 10px;
margin: 20px auto;
}
.box div{
border-bottom:1px solid #ccc;
padding-bottom: 10px;
margin-bottom: 8px;
}
.box input{
margin: 8px;
}
</style>
</head>
<body>
<div class="box">
<div>
<input type="checkbox" id="checkall" onclick="checkAll()"><label for="checkall">全选</label>
</div>
<input type="checkbox" name="item[]">选项1<br>
<input type="checkbox" name="item[]">选项2<br>
<input type="checkbox" name="item[]">选项3<br>
<input type="checkbox" name="item[]">选项4<br>
<input type="checkbox" name="item[]">选项5<br>
<input type="checkbox" name="item[]">选项6<br>
</div>
<script type="text/javascript">
function checkAll() {
var checkall,item;
checkall=document.getElementById('checkall');//获取全选
item=document.getElementsByName("item[]")//获取下面的勾选框
for(var i=0;i<item.length;i++){
if(checkall.checked){
item[i].checked=true;//当全选框被选中，勾选框选中
}else{
item[i].checked=false;//否则都不选中
}
}
}
</script>
</body>
</html>