​x
 
<html>
<head>
<script type="text/javascript">
function makeCheck(thisForm)
{
for (i = 0; i < thisForm.option.length; i++)
    {
    thisForm.option[i].checked=true
    }
}
​
function makeUncheck(thisForm)
{
for (i = 0; i < thisForm.option.length; i++)
    {
    thisForm.option[i].checked=false
    }
}
</script>
</head>
<body>
​
<form name="myForm">
<input type="button" value="选取" onclick="makeCheck(this.form)">
<input type="button" value="取消" onclick="makeUncheck(this.form)">
<br />
<input type="checkbox" name="option">苹果<br />
<input type="checkbox" name="option">桔子<br />
<input type="checkbox" name="option">香蕉<br />
<input type="checkbox" name="option">西瓜
</form>
​
</body>
</html>
​