Different fixes in double select ajax calls

main/inc/lib/extra_field.lib.php

@@ -424,6 +424,7 @@ class ExtraField extends model {
                     $jquery_ready_content .= '                        
                         $("#'.$first_select_id.'").on("change", function() {                   
                             var id = $(this).val();
+                            if (id) {
                                 $.ajax({ 
                                     url: "'.$url.'&a=get_second_select_options", 
                                     dataType: "json",
@@ -438,6 +439,9 @@ class ExtraField extends model {
                                         });                           
                                     },            
                                 });  
+                            } else {
+                                $("#second_extra_'.$field_details['field_variable'].'").empty();
+                            }
                         });';
                     
                     $first_id = null;
@@ -449,7 +453,8 @@ class ExtraField extends model {
                     }
 
                     $options = ExtraField::extra_field_double_select_convert_array_to_ordered_array($field_details['options']);
-                    $values = array();
+                    $values = array('' => get_lang('Select'));
+                    
                     $second_values = array();
                     if (!empty($options)) {                        
                         foreach ($options as $option) {                            

main/inc/lib/extra_field_value.lib.php

@@ -137,11 +137,13 @@ class ExtraFieldValue extends Model {
                         // only available for PHP 5.4  :( $result['field_value'] = $session_field_option->get($options[0])['id'].' -> ';
                         $result = $session_field_option->get($options[0]);
                         $result_second = $session_field_option->get($options[1]);
+                        if (!empty($result)) {
                             $result['field_value'] = $result['option_display_text'].' -> ';
                             $result['field_value'] .= $result_second['option_display_text'];
                         }
                     }            
                 }
+            }
             return $result;
         } else {
             return false;