求教:想用JS实现一个简单的复选框全选效果,为何实现不了?
想用JS实现一个简单的复选框全选效果,代码如下,可点了全选框后没有反应,哪里错了?请指点!谢谢!
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>复选框全选效果</title>
<script type="text/javascript">
function checkAll()
{
var tBox=document.getElementByName("box");
for(var i=0;i<tBox.length;i++)
{
if(document.getElementById("all").checked==true)
{
tBox[i].checked=true;
}
}
}
</script>
</head>
<body>
<input type="checkbox" name="box" value="1" />苹果<br />
<input type="checkbox" name="box" value="2" />三星<br />
<input type="checkbox" name="box" value="3" />诺基亚<br />
<input type="checkbox" name="box" value="4" />索尼<br />
<input type="checkbox" id="all" value="5" onclick="checkAll()" />全选
</body>
</html>
[解决办法]
<script type="text/javascript"> function checkAll() { var tBox = document.getElementsByName("box"); for (var i = 0; i < tBox.length; i++) { tBox[i].checked = document.getElementById("all").checked; } } </script></head><body> <form id="form1" runat="server"> <div> <input type="checkbox" name="box" value="1" />苹果<br /> <input type="checkbox" name="box" value="2" />三星<br /> <input type="checkbox" name="box" value="3" />诺基亚<br /> <input type="checkbox" name="box" value="4" />索尼<br /> <input type="checkbox" id="all" value="5" onclick="checkAll()" />全选 </div> </form></body></html>