名为Default的jQUery UI draggables示例说：
Enable draggable functionality on any DOM element.
但是我不能使它们在按钮元素上工作。
我修改了默认样本，如下所示：
我只是将div元素更改为带有type =“button”的按钮：
<!doctype html>
<html lang="en">
<head>
<Meta charset="utf-8">
<title>jQuery UI Draggable - Default functionality</title>
<link rel="stylesheet" href="../../themes/base/jquery.ui.all.css">
<script src="../../jquery-1.9.1.js"></script>
<script src="../../ui/jquery.ui.core.js"></script>
<script src="../../ui/jquery.ui.widget.js"></script>
<script src="../../ui/jquery.ui.mouse.js"></script>
<script src="../../ui/jquery.ui.draggable.js"></script>
<link rel="stylesheet" href="../demos.css">
<style>
#draggable { width: 150px; height: 150px; padding: 0.5em; }
</style>
<script>
$(function() {
$( "#draggable" ).draggable();
});
</script>
</head>
<body>
<button type="button" id="draggable" class="ui-widget-content">
<p>Drag me around</p>
</button>
<div class="demo-description">
<p>Enable draggable functionality on any DOM element. Move the draggable object by clicking on it with the mouse and dragging it anywhere within the viewport.</p>
</div>
</body>
</html>
我如何使一个按钮元素的draggables功能工作？
