JQuery函数显示依赖于隐藏HTML输入元素值的元素

在回答之前，我对JQUERY绝对是个新手。

我正在尝试创建一个DOM就绪函数，它接受隐藏HTML输入字段的值，如果值是。。。然后显示某个<div>类。

这是我的代码：

JS-更新

   $(document).ready(function(){
    var money = 19.95;
    /* not sure if this is written correctly, but this is supposed to
    check whether the hidden input element value is equal to var money */
   if ($("input[id='VAT_shipping'][type='hidden']").val() == money )  {
    $("#ac-wrapper").show(); 
    $("#popup").show();
    };
    // hide popup when user clicks on close button
    $(".close-btn").click(function(){
        $("#ac-wrapper").hide();
         // hide 
    });
    // hides the popup if user clicks anywhere outside the container
    $("#ac-wrapper").click(function(){
        $("#popup").hide();
    })
    // prevents the overlay from closing if user clicks inside the popup overlay
    $("#ac-wrapper.").click(function(e) {
    e.preventDefault();         
    var $this = $(this);
    var horizontalPadding = 30;
    var verticalPadding = 30;     
    });
});

HTML

<input type="hidden" id="VAT_shipping" value="<? print $shipping; ?>" />
<div id="ac-wrapper">
    <div id="popup">
      <center>
        <p>
       <strong> You have selected World Free Tax Zone - £19.95 for shipping. </strong>
        We will automatically remove the VAT - 20% from your order.
        Please click close to return to review your order.
        </p>
        <button class="close-btn">Close</button>
      </center>
    </div>
      </div>

CSS

#ac-wrapper {
    display:none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255,255,255,.6);
    z-index: 1001;
    }
#popup {
    width: 555px;
    height: 375px;
    background: #FFFFFF;
    border: 5px solid #000;
    border-radius: 25px;
    -moz-border-radius: 25px;
    -webkit-border-radius: 25px;
    box-shadow: #64686e 0px 0px 3px 3px;
    -moz-box-shadow: #64686e 0px 0px 3px 3px;
    -webkit-box-shadow: #64686e 0px 0px 3px 3px;
    position: relative;
    top: 200px; left: 375px;
    font-size: 16px;
    font-family: 'Oxygen', sans-serif;
    text-align: center
}
    .close-btn {
        cursor: pointer;
    font-family:Tahoma, Geneva, sans-serif;
    border: 1px solid #000000;
    color: #ffffff;
    background-color: #AC9E33;
    -webkit-border-radius: 3px;
    -moz-border-radius: 3px;
    border-radius: 3px;
    text-shadow: 0 1px 1px #000000;
    font: bold 11px Sans-Serif;
    text-transform:none;
    padding: 7px 12px;
    margin:0;
    background-image: -webkit-linear-gradient(transparent, rgba(0, 0, 0, 0.2));
    background-image: -moz-linear-gradient(transparent, rgba(0, 0, 0, 0.2));
    background-image: -o-linear-gradient(transparent, rgba(0, 0, 0, 0.2));
    background-image: -ms-linear-gradient(transparent, rgba(0, 0, 0, 0.2));
    background-image: linear-gradient(transparent, rgba(0, 0, 0, 0.2));
    -webkit-transition: background-color 0.3s;
    -moz-transition: background-color 0.3s;
    -o-transition: background-color 0.3s;
    -ms-transition: background-color 0.3s;
    transition: background-color 0.3s;
}
    .close-btn:hover {
    font-family:Tahoma, Geneva, sans-serif;
    border: 1px solid #000000;
    color: #ffffff;
    background-color: #515280;
    -webkit-border-radius: 3px;
    -moz-border-radius: 3px;
    border-radius: 3px;
    text-shadow: 0 1px 1px #000000;
    font: bold 11px Sans-Serif;
    text-transform:none;
    padding: 7px 12px;
    margin:0;
    background-image: -webkit-linear-gradient(transparent, rgba(0, 0, 0, 0.2));
    background-image: -moz-linear-gradient(transparent, rgba(0, 0, 0, 0.2));
    background-image: -o-linear-gradient(transparent, rgba(0, 0, 0, 0.2));
    background-image: -ms-linear-gradient(transparent, rgba(0, 0, 0, 0.2));
    background-image: linear-gradient(transparent, rgba(0, 0, 0, 0.2));
    -webkit-transition: background-color 0.3s;
    -moz-transition: background-color 0.3s;
    -o-transition: background-color 0.3s;
    -ms-transition: background-color 0.3s;
    transition: background-color 0.3s;
}

因此，jQuery函数检查shipping输入字段的值，如果它等于var money = 19.95，则显示ac-wrapper和嵌套的popup。然后，客户端可以使用"关闭btn"或单击元素外部来关闭此窗口。

有人能解释一下怎么做吗。