来个大佬看看哪里错了,能力有限看不出来
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" charset="uft-8" />
<title>函数调用</title>
<script type="text/javascript">
function add2() //定义函数
{
var sum=5+6;
alert("sum");
}add2();
</script>
</head>
<body>
<form>
<input type="button" value="点击" onclick="add2()" />
</form>
</body>
</html>