为什么这个YUI3示例中的代码对我不起作用? HTML:
<!-- The original body content is above -->
<div id=\"form_container\">
    <form class=\"yui3-widget-bd\" id=\"theme_form\" action=\"#\" method=\"get\">
            <h3>Update Theme</h3>
            <label for=\"font_size\">Font size:</label>
            <input type=\"text\" size=\"3\" id=\"font_size\" value=\"16px\">

            <label for=\"heading_color\">Heading color:</label>
            <input type=\"text\" size=\"12\" id=\"heading_color\" value=\"#005A9C\">

            <label for=\"link_hover\">Link hover backgound:</label>
            <input type=\"text\" size=\"12\" id=\"link_hover\" value=\"#ffa\">
        <input type=\"submit\">
// Create a new YUI instance, requiring stylesheet, overlay, slider, and the
// dd-plugin to make the overlay draggable
    filter: \'raw\'
}).use(\"stylesheet\", \"overlay\", \"slider\", \"dd-plugin\", function(Y) {

    var myStyleSheet = new Y.StyleSheet(),
        overlayContent = Y.one(\'#form_container\'),
        overlay, slider, slider_container, fontSizeInput;

        // Create the Overlay, using the form container as the contentBox.
        // The form is assigned a class yui-widget-bd that will be automatically
        // discovered by Overlay to populate the Overlay\'s body section.
        // The overlay is positioned in the top right corner, but made draggable
        // using Y.Plugin.Drag, provided by the dd-plugin module.
        overlay = new Y.Overlay({
            srcNode: overlayContent,
            width: \'225px\',
            align: {
                points: [Y.WidgetPositionAlign.TR, Y.WidgetPositionAlign.TR]
            plugins: [Y.Plugin.Drag]

    // Slider needs a parent element to have the sam skin class for UI skinning

    // Progressively enhance the font-size input with a Slider
    fontSizeInput = Y.one(\'#font_size\');
    fontSizeInput.set(\'type\', \'hidden\');
    Y.Node.create(\'6 <span></span> 36\'), fontSizeInput);

    slider_container = fontSizeInput.previous(\"span\");

    // Create a Slider to contain font size between 6px and 36px, using the
    // page\'s current font size as the initial value.
    // Set up an event subscriber during construction to update the replaced
    // input field\'s value and apply the change to the StyleSheet
    slider = new Y.Slider({
        length: \'100px\',
        min: 6,
        max: 36,
        value: parseInt(Y.one(\'body\').getStyle(\'fontSize\')) || 13,
        after: {
            valueChange: function(e) {
                var size = e.newVal + \'px\';

                this.thumb.set(\'title\', size);
                fontSizeInput.set(\'value\', size);

                myStyleSheet.set(\'body\', {
                    fontSize: size

    // The color inputs are assigned keyup listeners that will update the
    // StyleSheet if the current input value is a valid CSS color value
    // The heading input affects all h1s, h2, and h3s
    Y.on(\'keyup\', function(e) {
        var color = this.get(\'value\');


        if (isValidColor(color)) {
            console.log(\"Valid color\", myStyleSheet);

            myStyleSheet.set(\'h1, h2, h3\', {
                color: color
    }, \'#heading_color\');

    // The link hover affects the background color of links when they are
    // hovered. There is no way other than via stylesheet modification to
    // change pseudo-class styles.
    Y.on(\'keyup\', function(e) {
        var color = this.get(\'value\');

        if (isValidColor(color)) {
            myStyleSheet.set(\'a:hover\', {
                backgroundColor: color
    }, \'#link_hover\');

    // Progressive form enhancement complete, now prevent the form from
    // submitting normally.
    Y.on(\'submit\', function(e) {
    }, \'#theme_form\');

    // A rudimentary validator to make sure we\'re not trying to set
    // invalid color values in StyleSheet.

    function isValidColor(v) {
        return /^#[0-9a-f]{3}(?:[0-9a-f]{3})?$/i.test(v) || /^rgb\\(\\s*\\d+\\s*,\\s*\\d+\\s*,\\s*\\d+\\s*\\)$/.test(v) || /^[a-z]{3,}$/i.test(v);

/* For supporting browsers, the overlay is rendered semi-transparent with
* fancy rounded corners */
.yui3-overlay {
    background: rgba(128,128,128,0.3);
    -moz-border-radius: 10px;
    -webkit-border-radius: 10px;
    border-radius: 10px;
    padding: 7px;
    cursor: move;

.yui3-overlay-content {
    background: rgba(205,205,205,0.3);
    -moz-border-radius: 10px;
    -webkit-border-radius: 10px;
    border-radius: 10px;
    padding: 1px;

.yui3-overlay form {
    background: #f2fbff;
    border: 2px solid #fff;
    -moz-border-radius: 10px;
    -webkit-border-radius: 10px;
    border-radius: 10px;
    margin: 0;
    padding: 0;
    font-size: 13px;

.yui3-overlay fieldset {
    border: 1px solid #bcd;
    -moz-border-radius: 10px;
    -webkit-border-radius: 10px;
    border-radius: 10px;
    margin: 0;
    padding: 20px;

.yui3-overlay h3 {
    border-bottom: 2px solid #fff;
    color: #479;
    background: transparent;
    margin: 0;
    font-size: 175%;

.yui3-overlay label {
    display: block;
    margin: 1.3em 0 0.5ex;
    font-weight: bold;
    color: #003;

.yui3-overlay p {
    margin: 2em 0 0;

/* override the move cursor for the Slider */
.yui3-overlay .yui3-slider:hover {
    cursor: default;
        您的标签缺少class =“ \” yui3-sam-sam yui-skin-sam \“     
        这不是支持调试的最佳论坛。 欢迎您在freenode的#yui频道中提问,而不要在此处进行缓慢的来回调试。