CHECKBOX全选问题
<html>
<head>
<title>无标题页</title>
</head>
<script>
function a(){
var v = document.getElementById('a');
var m = document.getElementById('b');
var n = document.getElementById('c');
if(v.checked==true){
m.checked = true;
n.checked = true;
}
else{
m.checked=false;
n.checked=false;
}
}
</script>
<body>
<input type="checkbox" name="a" onclick="a()">
<input type="checkbox" name="b" id="b" >
<input type="checkbox" name="c" id="c" >
</body>
</html>