Delete attachment data from tables SOOD AND SRGBTBREL

I have successfully attached files from application server with purchase order .

I have used fm in following order.

SO_FOLDER_ROOT_ID_GET

SO_OBJECT_INSERT

BINARY_RELATION_CREATE_COMMIT

.

Now i want to delete that attachments i have used some fms but it doesn't work .

BINARY_RELATION_DELETE_COMMIT. it doesnt show any attachments when you open me22 transaction and try to view the attachments . but i can still see the attachment data in SOOD AND SRGBTBREL.

SO_ATTACHMENT_DELETE and  SO_OBJECT_DELETE didnt help me too .