<html>
<head>
<script type="text/javascript">
function testCheckBox(){
var vehicle = document.getElementById(‘vehicle‘);
for (var i=0; i < vehicle.length; i++){
alert(vehicle[i].checked);
if (trucks[i].checked){
alert(‘at least one was selected‘);
return true;
}
}
alert(‘Please select one‘);
return false;
}
</script>
</head>
<body>
<form>
<input type="checkbox" name="vehicle" value="Bike" /> I have a bike<br />
<input type="checkbox" name="vehicle" value="Car" /> I have a car
<br />
<input type="button" name="test" value="test" onclick="testCheckBox();" />
</body>
</html>原文：http://www.cnblogs.com/qinse/p/4329350.html