title: add param to FB.login() callback function if no session is returned by FB.getLoginStatus()
body: <p>i'm having trouble building a function fbPostToWall(picUrl) that uses FB.getLoginStatus() to post a received picture url to a users wall. This part works fine as there is a session response:</p>
  
  <pre><code>function fbPostToWall(picUrl) {
  
      FB.getLoginStatus(function(response) {
  
          if (response.session) {
  
              // logged in and connected user, someone you know
              FB.ui(
                  {
                      method: 'feed',
                      picture: picUrl,
                      ...
                  },
                  function(response) {
                      if (response &amp;&amp; response.post_id) {
                          alert("Post was successful");
                      } else {
                          alert("Post was not successful");
                      }
                  }
              );
  
          } else {
  
              // no user session available, someone you dont know
              FB.login(myCallbackFn);
          }
      });
  
  }
  </code></pre>
  
  <p>But if there is no session response, i try to call FB.login(myCallbackFn) with my own callback function "myCallbackFn" which looks like this:</p>
  
  <pre><code>function myCallbackFn(response) {
      // if we dont have a session, just hide the user info
      if (!response.session) {
          return;
      }
  
      if(response.session) {
  
          //get picture previously saved in Session
          $.post("picture.php", { getPicture: "" },
  
              function(data){
  
                  // logged in and connected user, someone you know
                  FB.ui(
                      {
                          method: 'feed',
                          ...
                      },
                      function(response) {
                          if (response &amp;&amp; response.post_id) {
                              alert("Post was successful");
                          } else {
                              alert("Post was not successful");
                          }
                      }
                  );
  
              }
          );              
  
      }
  }
  </code></pre>
  
  <p>When the callback part gets called, the fb popup window doesn't open, instead the browsers popup warning appears. When i grant the permission to open the popup, i can login with fb and post the picture to my wall. But now a new popup window opens (Title "XD Proxy") which stays opened after the post was submitted. What is this and how can i avoid that? Can i simplify both functions by adding the picture url to the callback function as a param? Thanks!</p>