setInterval works online on same sytem (with 2 browsers open) but not online on separate systems
<p>I have a setinterval code updating a div. This works fine when tested in two separate browsers on the same system but when I test online on say a separate mac and PC and it stops. </p>

<p>The code is as follows:-</p>

<p>Javascript:</p>

<pre><code>    function setupAjaxIntervalDiscuss(){
    setInterval(function()
    {
    var datastring = 'refreshchat=true&amp;projid=' + proj_id + '&amp;uid=' + uid;
    ajaxUpdateDiscussion(datastring);
    }, 2000);
    }

   function ajaxUpdateDiscussion(ajaxdata){
    $.ajax({
        type: "POST",
        url: "uploaddata.php",
        data: ajaxdata,
        success: function(data){
        $("#discussresult").html(data);
        refreshNav();//Updating a scrollbar styled with JS
                    }
        });
  }
</code></pre>

<p>PHP(this update correctly just here for ref) :</p>

<pre><code> if(isset($_POST["refreshchat"])){
 $user_id= $_POST['uid'];
 $proj_id=$_POST['projid'];
 echo '&lt;img class="closeddiscuss" src="images/closey.png" title="close" alt="close"/&gt;'; 
  $get_discuss_query = "SELECT * FROM discuss INNER JOIN user ON discuss.user_id=user.user_id
                        WHERE discuss.project_id=$proj_id ORDER BY discuss_id DESC";
                        $get_discuss_result=mysql_query($get_discuss_query);
                        while($row=mysql_fetch_assoc($get_discuss_result)){
                        $text = nl2br($row['discuss_text']);
                        $name = $row['user_name'];
                        $user_profileimageurl = $row['user_profileimageurl'];
                        echo '&lt;div class="discussbubble"&gt;&lt;p&gt;'.$text.'&lt;/p&gt;&lt;img class="smallprofileimage" src="'.$user_profileimageurl.'" alt="user profile image"/&gt; by '.$name.'&lt;/div&gt;';
                        }
   }
</code></pre>
