The json encode did not return response after calling the function of fb post to wall

I have a link which posted data to another page vote.php through jquery.

When I click on that link, it return the state according to the condition. If that user posted the vote before then it displayed the "already voted" other wise "Your vote posted".

All was working fine.

I am using the facebook post to wall sdk.

Now when I call the fb_publish_on_wall function from the vote.php, the message successfully posted to my fb wall but it did not return the state of the vote like "Your vote posted".

What is the problem. When I comment out that line where I am calling the fb_publish_on_wall function then It works fine.

I think the jquery did not get response from vote.php after calling the fb_publish_on_wall function.

How will I fix this?

UPDATED: Here is the fb_publish_on_wall function

function fb_publish_on_wall($message,$link,$picture,$name,$description,$user_facebook2)

{

    $message = str_replace(array('<br />', '<br>'), "\n", $message);

        $description = str_replace(array('<br />', '<br>'), "\n", $description);

        $name = str_replace(array('<br />', '<br>'),"\n", $name);

        $link = str_replace(array('<br />', '<br>'), "\n", $link);



        global $facebook;



                $publishStream = $facebook->api("/$user_facebook2/feed", 'post', array(

                    'message' => "$message", 

                    'link'    => "$link",

                    'picture' => "$picture",

                    'name'    => "$name",

                    'description'=> "$description"

                    ));



        print $user_facebook2;







}

UPDATED: vote.php. This file is big. SO I am only displaying the that two lines from vote.php

echo json_encode(array("state"=>"<span style='color:#8DA326'>".l("Your vote posted").".</span>"));



    fb_publish_on_wall($message,$link,$picture,$name,$description,$user_facebook2);