Hi. I created a Custom Field Type to add service IDs to Hotels (which is a CPT). I defined the field type as: tb-service-id. Then I add this field to the corresponding metabox. I've set:
'clone' => true
and the button to clone the field appears, but the field is generated with the same ID as the other one:
In the html mehod of the Custom Field Type I create a select and set the ID to the variable: $field['id'] which gives the value: '_hotel_tb_service_id'.
Any help would be much appreciated