function add_custom_field($name, $label, $data_type, $max_size, $required_option, $default_value, $deleted, $ext1, $ext2, $ext3, $audited, $mass_update = 0, $duplicate_merge = 0)
 {
     $module_name = $this->module_name;
     $fields_meta_data = new FieldsMetaData();
     $fields_meta_data->name = $name;
     $fields_meta_data->label = $label;
     $fields_meta_data->module = $module_name;
     $fields_meta_data->data_type = $data_type;
     $fields_meta_data->max_size = $max_size;
     $fields_meta_data->required_option = $required_option;
     $fields_meta_data->default_value = $default_value;
     $fields_meta_data->deleted = $deleted;
     $fields_meta_data->ext1 = $ext1;
     $fields_meta_data->ext2 = $ext2;
     $fields_meta_data->ext3 = $ext3;
     $fields_meta_data->audited = $audited;
     $fields_meta_data->duplicate_merge = $duplicate_merge;
     $fields_meta_data->mass_update = $mass_update;
     $fields_meta_data->insert();
     $custom_table_name = $this->_get_custom_tbl_name();
     $custom_table_exists = CustomFieldsTableSchema::custom_table_exists($custom_table_name);
     $custom_fields_table_schema = new CustomFieldsTableSchema($custom_table_name);
     if (!$custom_table_exists) {
         $custom_fields_table_schema->create_table();
     }
     $result = $custom_fields_table_schema->add_column($name, $data_type, $required_option, $default_value);
     return $result;
 }