title: Multiple Ajax Calls while one Ajax call is still running
body: <p>I got some progressbar Update Issues. What I like to do is, fire a ajax call which takes some time to complete and during the this call I'd like to fire ajax calls, set by an interval, to update my progressbar.</p>
  
  <p>Since I could not find a solution and only found the Browser's restriction, which would match here. It's always max 2 calls active.</p>
  
  <p>Still, my second call stays pending in Google Chrome,  untill my first (main) call finished.</p>
  
  <p>EDIT: full jquery script</p>
  
  <pre><code>// update cars cache
  $('#cars_cache_update_run').bind('click', function(){
      // remove button
      $(this).remove();
  
      // hide import widgets
      $('#products_import_widget').css('display', 'none');
      $('#vehicles_import_widget').css('display', 'none');
      $('#orders_import_widget').css('display', 'none');
      $('#test_data_widget').css('display', 'none');
  
      // show blind
      $('#cars_cache_update_info').css('display', 'none');
      $('#cars_cache_update_blind').css('display', 'inline');
  
      var carsUpdateInterval = setInterval(function() {
          getImportState('http://localhost/index.php/import/import_state/cache_update', 'cars_import_progressbar');
      }, 1000);
      // ajax request
      $.ajax({
          url: "http://localhost/index.php/import/cars_cache",
          async : true,
          success: function(data){
              $('#cars_cache_update_blind').css('display', 'none');
              $('#cars_cache_update_success').css('display', 'inline');
              clearInterval(carsUpdateInterval);
  
          },
          error: function(thrownError){
              $('#cars_cache_update_blind').css('display', 'none');
              $('#cars_cache_update_error').css('display', 'inline');
              $('#cars_cache_update_error_msg').html(thrownError);
          }
      });
  });
  
  function getImportState(url, id)
  {
      $.ajax({
          url: url,
          success: function(data){
              var json = $.parseJSON(data);
  
              $.each(json, function(i, item) {
                  var progressbar_value = json[i]['state'];
                  $( "#"+id ).progressbar({
                      value: progressbar_value
                  });
              })
          }
      });
  }
  </code></pre>
  
  <p>Another funny thing, if I call the interval request by $.get I'll get a strange error..
  Working with Codeignitor Framework.</p>
  
  <pre><code>GET http://localhost/[object%20Object] 404 (Not Found) jquery.1.7.min.js:4
  send jquery.1.7.min.js:4
  f.extend.ajax jquery.1.7.min.js:4
  f.(anonymous function) jquery.1.7.min.js:4
  (anonymous function)
  </code></pre>
  
  <p>Many Thanks for your help already, been trying for hours now.. Maybe I'm just a noob.. Haha.</p>
  
  <p>rootless</p>