function signup() {
        FB.api('/me', function (response) {
            if (response.id != "") {
                $.ajax({
                    method: "POST",
                    url: "bin/ajax.php",
                    data: {action: "fb-login", fbid: response.id}
                }).done(function (msg) {
                    var json = $.parseJSON(msg);
                    if(json.status==="failure") {
                        if(response.id!="") {
                            $.ajax({
                                method: "POST",
                                url: "bin/ajax.php",
                                data: {action: "fb-signup", fbid: response.id, name: response.name}
                            }).done(function (msg) {
                            var json1 = $.parseJSON(msg);
                            console.log(json1.status);
                            if(json1.status==="failure") {
                                ga('send', 'event', 'Login and Signup','Signup Failure', 'Facebook');
                                $('#signup_error').html("<div class='alert alert-danger'><p><b>Error! </b>There's a problem please try later..</div>");
                            }
                            else {
                                ga('send', 'event', 'Login and Signup','Signup Success', 'Facebook');
                                $('#signup_error').html("<div class='alert alert-success'><p><b>Signed Up Successful</b></div>");
                                 <?php

                                if(isset($_SESSION['intend_ebook'])) {
                                $intend_id = $_SESSION['intend_ebook'];
                                ?>

                                window.location.href="read.php?book=<?php echo $intend_id; ?>";
                                <?php
                                }
                                else if(isset($_GET['back'])) {
                                    @session_start();
                                    $_SESSION['su'] = 1;
                                    $_SESSION['back'] = $_GET['back'];

                                    ?>
                                    window.location.href="book/<?php echo $_GET['back'];?>";
                                    <?php
                                }

                                else {
                                ?>
                                        window.location.href="dashboard/membership.php";

                                <?php
                                }
                                ?>

                            }
                            });

                        }
                        else {
                            ga('send', 'event', 'Login and Signup','Login Failure', 'Facebook');
                            $('#login_error').html("<div class='alert alert-danger'><p><b>Error! </b></div>");
                        }
                    }
                    else {
                        ga('send', 'event', 'Login and Signup','Login Success', 'Facebook');

                        <?php
                        @session_start();
                         if(isset($_SESSION['intend_ebook'])) {
                                $intend_id = $_SESSION['intend_ebook'];
                                ?>
                                window.location.href="read.php?book=<?php echo $intend_id; ?>";
                                <?php
                                }
                         else {
                             ?>
                        window.location.href="dashboard/membership.php";

                    <?php
                         }
                         ?>


                    }
                });
            }
        });
    }