the code for the modal delete window with the Delete ID and delete button elements is inside the recordset repeat region:
<div class="modal-footer">
<input type="hidden" name="WADADeleteRecordID" id="WADADeleteRecordID" value="<?php echo($customerlist->getColumnVal("idcustomers")); ?>" />
<button type="button" class="btn btn-default" data-dismiss="modal">Annulla</button>
<input name="Delete" class="btn btn-danger" type="submit" id="Delete">
</div>
it should be after the recordset repeat region.