$(document).ready(function() {
                    
                    $('a.delete-from-favorites').live('click', function() {
                        
                        // Do nothing, if request is on process.
                        if (this.className.search('disabled') != -1)
                        {
                            return false;
                        }
                        
                        // Disable this link and send a request.
                        this.className += ' disabled';
                        var link = this;
                        
                        $.ajax({
                            url: this.href,
                            success: function(response)
                            {
                                var response = eval('('+response+')');
                                
                                if(response.status == 'success')
                                {
                                    var listItem = link.parentNode.parentNode;
                                    var list = listItem.parentNode;
                                    
                                    list.removeChild(listItem);
                                    formFavotiresList();
                                    formFavotiresList();
                                    
                                    if (ScrollableArea('favorites', 'vertical') == true)
                                    {
                                        modifyScrollbarStyle('favorites');
                                    }
                                    
                                    var favoritesItemsCount = document.getElementById('favorites-items-count');
                                    favoritesItemsCount.innerHTML = response.favorits['items'];
                                }
                                else
                                {
                                    link.className = link.className.substring(0, link.className.search(' disabled'));
                                }
                            }
                        });
                        
                        return false;
                    });

var response = eval('('+response+')');

{"status":"success","favorits":{"items":10}}

{"status":"success","favorits":{"items":10}}

$.ajax({
  url: this.href,
  dataType: 'json', // явно указываем тип данных
  success: function(response) // response содержит js-объект
  {
  // уберите var response = eval('('+response+')');