Facebook登录窗口出现和消失没有登录应用程序

我使用Javascript SDK创建了一个facebook应用程序。它对我来说很好(也许是因为应用程序链接到我的帐户)，但它不适合其他用户。当用户点击登录按钮，对话框出现，并要求用户的facebook用户名和密码。但随后对话框消失，登录按钮仍然在那里。当用户再次单击Login按钮或刷新页面时，对话框会很快出现并消失。用户确实登录了他的facebook帐户，但他没有登录到应用程序。

<div id="fb-root"></div>
<script>
  window.fbAsyncInit = function() {
  FB.init({
    appId      : 'xxxxxxxxxxx', // App ID
    status     : true, // check login status
    cookie     : true, // enable cookies to allow the server to access the session
    xfbml      : true  // parse XFBML
  });
  // Here we subscribe to the auth.authResponseChange JavaScript event. This event is fired
  // for any authentication related change, such as login, logout or session refresh. This means that
  // whenever someone who was previously logged out tries to log in again, the correct case below 
  // will be handled. 
  FB.Event.subscribe('auth.authResponseChange', function(response) {
    // Here we specify what we do with the response anytime this event occurs. 
    if (response.status === 'connected') {
      // The response object is returned with a status field that lets the app know the current
      // login status of the person. In this case, we're handling the situation where they 
      // have logged in to the app.
      testAPI();
    } else if (response.status === 'not_authorized') {
      // In this case, the person is logged into Facebook, but not into the app, so we call
      // FB.login() to prompt them to do so. 
      // In real-life usage, you wouldn't want to immediately prompt someone to login 
      // like this, for two reasons:
      // (1) JavaScript created popup windows are blocked by most browsers unless they 
      // result from direct interaction from people using the app (such as a mouse click)
      // (2) it is a bad experience to be continually prompted to login upon page load.
      FB.login(function(response) {
   if (response.authResponse) {
     console.log('Welcome!  Fetching your information.... ');
     FB.api('/me', function(response) {
       console.log('Good to see you, ' + response.name + '.');
     });
   } else {
     console.log('User cancelled login or did not fully authorize.');
   }
 }); 
    } else {
      // In this case, the person is not logged into Facebook, so we call the login() 
      // function to prompt them to do so. Note that at this stage there is no indication
      // of whether they are logged into the app. If they aren't then they'll see the Login
      // dialog right after they log in to Facebook. 
      // The same caveats as above apply to the FB.login() call here.
      FB.login(function(response) {
   if (response.authResponse) {
     console.log('Welcome!  Fetching your information.... ');
     FB.api('/me', function(response) {
       console.log('Good to see you, ' + response.name + '.');
     });
   } else {
     console.log('User cancelled login or did not fully authorize.');
   }
 });
    }
  });
  };
  // Load the SDK asynchronously
  (function(d){
   var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
   if (d.getElementById(id)) {return;}
   js = d.createElement('script'); js.id = id; js.async = true;
   js.src = "//connect.facebook.net/en_US/all.js";
   ref.parentNode.insertBefore(js, ref);
  }(document));
  // Here we run a very simple test of the Graph API after login is successful. 
  // This testAPI() function is only called in those cases. 
  function testAPI() {
    console.log('Welcome!  Fetching your information.... ');
    FB.api('/me', function(response) {
    userData = response;
    document.getElementById('name').value=userData.name;
    document.getElementById('email').value=userData.email;

    });
  }
  function submit(){
    FB.api('/me', function(response) {
    userData = response;
    console.log(userData);
    var form = $("#login-form form");
    var serializedData=form.serialize()+'&id='+userData.id+'&email='+userData.email;
    console.log(serializedData);
    $.ajax({
    url: './abc.php',
    type: 'POST',
    data: serializedData,
    dataType:'json',
    success: function (response) {},
    error: function (xhr, ajaxOptions, thrownError){}

    }); });
  return false;
  }
  function logout(){
  FB.logout(function(response) {
        // Person is now logged out
        console.log('You have logged out of Bookatdoor. Thank you!');
        location.reload();
    });
  }
  </script>
<!--
  Below we include the Login Button social plugin. This button uses the JavaScript SDK to
  present a graphical Login button that triggers the FB.login() function when clicked.
  Learn more about options for the login button plugin:
  /docs/reference/plugins/login/ -->
<fb:login-button show-faces="true" width="200" max-rows="1"></fb:login-button>
<br>
<div id="login-form">
<form action="" method="POST" onsubmit="submit();return false;">
Name: <input type="text" name="name" id="name" placeholder="Name">
Email: <input type="email" name="email" id="email" placeholder="Email" disabled>
Password: <input type="password" name="pwd" placeholder="Password">
Re-Password: <input type="password" placeholder="Re-Type Password">
College: <select name="college">
<?php 
include "./connect.php";
$query="select * from college";
$result=mysqli_query($con,$query) or die(mysqli_error($con));
while ($row=mysqli_fetch_array($result))
{
    echo "<option value='".$row['ID']."'>".$row['NAME']."</option>";
}
?>
</select>
</form>
<button onclick="submit()">Submit</button>
</div>
<button onclick="logout()">Logout</button>