jQuery：通过选择SELECT OPTION克隆元素

$(\'select#cars\').change(function() {
   // Get number of cars chosen
   var carsCount = $(this).val(),
       // Get a reference to the first input group so we can clone it
       carInput = $(\'#car-inputs div:first\');

   // Clone per number chosen
   for (var i = 0; i < carsCount; i++) {
       // Insert clone after original.
       // IRL, you probably need to do some preprocessing on it first.
       carInput.clone().insertAfter(carInput);
   }
});