var ajax = new Array();

function getCityList(sel)
                                                         {
                                                           var countryCode = sel.options[sel.selectedIndex].value;
                                                           document.getElementById('model').options.length = 0;  // Empty city select box
                                                           if(countryCode.length>0){
                                                             var index = ajax.length;
                                                             ajax[index] = new sack();
                                                             
                                                             ajax[index].requestFile = 'getcars.php?carCode='+countryCode;  // Specifying which file to get
                                                             ajax[index].onCompletion = function(){ createCities(index) };  // Specify function that will be executed after file has been found
                                                             ajax[index].runAJAX();    // Execute AJAX function
                                                           }
                                                         }

                                                         function createCities(index)
                                                         {
                                                           var obj = document.getElementById('model');
                                                           eval(ajax[index].response);  // Executing the response from Ajax as Javascript code  
                                                         }


                                                         function getSubCategoryList(sel)
                                                         {
                                                           var category = sel.options[sel.selectedIndex].value;
                                                           document.getElementById('dhtmlgoodies_subcategory').options.length = 0;  // Empty city select box
                                                           if(category.length>0){
                                                             var index = ajax.length;
                                                             ajax[index] = new sack();
                                                             
                                                             ajax[index].requestFile = 'getSubCategories.php?category='+category;  // Specifying which file to get
                                                             ajax[index].onCompletion = function(){ createSubCategories(index) };  // Specify function that will be executed after file has been found
                                                             ajax[index].runAJAX();    // Execute AJAX function
                                                           }
                                                         }
                                                         function createSubCategories(index)
                                                         {
                                                           var obj = document.getElementById('dhtmlgoodies_subcategory');
                                                           eval(ajax[index].response);  // Executing the response from Ajax as Javascript code  
                                                         }