you need to add code to the submit button to set a hidden element to the selected ID
create a hidden form element on the page named deleteID, make sure deleteID is used for both the name and ID of the hidden element.
then edit the submit button to add an onclick event to set the deleteID:
<input name="deleteproduct" type="submit" class="custom_button_red" id="deleteproduct" value="-" onClick="document.getElementById('deleteID').value=<?php echo $row_Recordsetfindallprodid['johnsid']; ?>">
then in the delete record behavior, set the delete ID to use the deleteID hidden element.