<h1>我的第一段 JavaScript</h1>
<p>请输入数字。如果输入值不是数字，浏览器会弹出提示框。</p>
<input >
<script>
function myFunction()
{
var x=document.getElementById("demo").value;
if(x==""||isNaN(x))
{
alert("Not Numeric");
}
}
</script>
<button type="button" onclick="myFunction()">点击这里</button>
</body>
</html>
<html>
<head>
<script type="text/javascript" src="/jquery/jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$(".btn1").click(function(){
$("p").slideToggle();
});
});
</script>
</head>
<body>
<p>This is a paragraph.</p>
<button class="btn1">Toggle</button>
</body>
</html>