Although the same method works when I am on the results page, it doesn't do anything when on details page.
Hello nico on the detail page its even more easier to delete a file than the result pages.
Add inside the form a new hidden field name it what ever like oldFile and then bind the record of the file to it example
<input name="oldFile" type="hidden" id="oldFile" value="<?php echo $row_WADAproducts['ProductThumb']; ?>" />
add now the behavior for deleting files
on this screen select for the trigger
Trigger: Button: Delete pressed
Delete folder: select where you have the file
File Name: <?php echo((isset($_POST["oldFile"]))?$_POST["oldFile"]:"") ?>
For file name bind the hidden field you created
and it should work
Now if it where the result page let me knw and ill guid you threw it