Javascript 如果单击关闭按钮，如何防止弹出类似Facebook的框

我想在我的网站上添加一个类似Fb的弹出框，当访问者向下滚动时，弹出框就会出现。我想当访问者点击关闭按钮时，弹出框在15天内不会出现。但当我点击它关闭，但它显示当我向上或向下滚动。有人能帮我吗？ 我的代码是：

<!-- FB Popup Likebox Start -->
            <div class="fb-pop-like-box" id="fb-popup-like-box">
                <p style="text-align: center;">Hey, Like Us on Facebook!</p>
                <div class="fb-like-box" data-href="https://www.facebook.com/ifo4all" data-width="300" data-height="200" data-colorscheme="light" data-show-faces="true" data-header="false" data-stream="false" data-show-border="true"></div>
                <div class="no-show"><a href="#">Close: I already Like if04all!</a></div>
            </div>      
                <script type="text/javascript">
                    $(function () {
                        $("#fb-popup-like-box").hide();
                        $(window).scroll(function () {
                            if ($(this).scrollTop() > 2100) {
                                $('#fb-popup-like-box').slideDown('slow');
                            } else {
                                $('#fb-popup-like-box').slideUp('slow');
                            }
                        });
                    });
                    jQuery(document).ready(function(){

                    if(readFBCookie('squenched') != null) { 
                                jQuery('#fb-popup-like-box').css("display", "none");
                        }

                        jQuery('.no-show a').live("click",function(event){
                            event.preventDefault();
                            jQuery('#fb-popup-like-box').css("display", "none");
                            var days=15;
                            var date = new Date();
                            date.setTime(date.getTime()+(days*24*60*60*1000));
                            var expires = "; expires="+date.toGMTString();
                            document.cookie = "squenched=1"+expires+"; path=/";
                            return false;
                        });
                        function readFBCookie(name) {
                                  var nameEQ = name + "=";
                                  var ca = document.cookie.split(';');
                                  for(var i=0;i < ca.length;i++) {
                                    var c = ca[i];
                                    while (c.charAt(0)==' ') c = c.substring(1,c.length);
                                    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
                                  }
                                  return null;
                        }
                    });
                </script>
<!-- FB Popup Likebox Start End -->

---

非常感谢您的回答，我是JS的noobs，它不显示弹出窗口，控制台日志未捕获引用错误：未定义readFBCookie

$(function () {
                    $("#fb-popup-like-box").hide();
                    $(window).scroll(function () {
                        if(readFBCookie('squenched') == null) { 
                        if ($(this).scrollTop() > 2100) {
                            $('#fb-popup-like-box').slideDown('slow');
                        } else {
                            $('#fb-popup-like-box').slideUp('slow');
                        }
                        }
                    });
                });
                jQuery(document).ready(function(){

                if(readFBCookie('squenched') != null) { 
                            jQuery('#fb-popup-like-box').css("display", "none");
                    }

                    jQuery('.no-show a').live("click",function(event){
                        event.preventDefault();
                        jQuery('#fb-popup-like-box').css("display", "none");
                        var days=15;
                        var date = new Date();
                        date.setTime(date.getTime()+(days*24*60*60*1000));
                        var expires = "; expires="+date.toGMTString();
                        document.cookie = "squenched=1"+expires+"; path=/";
                        return false;
                    });
                    function readFBCookie(name) {
                              var nameEQ = name + "=";
                              var ca = document.cookie.split(';');
                              for(var i=0;i < ca.length;i++) {
                                var c = ca[i];
                                while (c.charAt(0)==' ') c = c.substring(1,c.length);
                      if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
                              }
                              return null;
                    }

                });