<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<script type="text/javascript">
window.οnlοad=function(){
var all=document.getElementById("all");
all.οnclick=function(){
var products=document.getElementsByName("product");
for (var i=0;i<products.length;i++) {
products[i].checked=all.checked;
}
};
var products=document.getElementsByName("product");
for (var i=0;i<products.length;i++) {
products[i].οnclick=hand;
}
function hand(){
var curr=this.checked;
if (curr==false) {
all.checked=false;
return;
}
for (var j=0;j<i;j++) {
if (products[j].checked==false) {
all.checked=false;
return;
}
}
all.checked=true;
}
}
</script>
</head>
<body>
<form>
<table align="center" style="margin-top:50px; ">
<tr><td><input type="checkbox" id="all">全选</input></td></tr>
<tr>
<td><input type="checkbox" name="product">篮球</input></td>
</tr>
<tr>
<td><input type="checkbox" name="product">足球</input></td>
</tr>
<tr>
<td><input type="checkbox" name="product">羽毛球</input></td>
</tr>
<tr>
<td><input type="checkbox" name="product">棒球</input></td>
</tr>
</table>
</form>
</body>
</html>
