<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<script type="text/javascript">
function check(){
document.getElementById("ck1").checked=true;
document.getElementById("ck2").checked=true;
document.getElementById("ck3").checked=true;
document.getElementById("ck4").checked=true;
}
function uncheck(){
document.getElementById("ck1").checked=false;
document.getElementById("ck2").checked=false;
document.getElementById("ck3").checked=false;
document.getElementById("ck4").checked=false;
}
function panduan(){
if(document.getElementById("ck").checked){
check();
}else{
uncheck();
}
}
</script>
<body>
<input type="checkbox" id="ck1"/>篮球<br />
<input type="checkbox" id="ck2"/>足球<br />
<input type="checkbox" id="ck3"/>排球<br />
<input type="checkbox" id="ck4"/>乒乓球<br />
<input type="checkbox" id="ck" onclick="panduan()"/>全选<br />
</body>
</html>