ABAP: Check if a customer is blocked for sales support

This is relatively simple, but it's best to keep it here for future use.

FORM check_if_customer_is_blocked USING a_cust_id TYPE kunnr.
 DATA :
   is_blocked TYPE cassd_x.

 SELECT SINGLE cassd
   INTO is_blocked
   FROM kna1
   WHERE kunnr = a_cust_id.

 IF NOT is_blocked IS INITIAL.
   MESSAGE e888(sabapdocu) WITH 'Customer is blocked!'.
 ENDIF.

 SELECT SINGLE cassd
  INTO is_blocked
  FROM knvv
  WHERE kunnr = a_cust_id.

 IF NOT is_blocked IS INITIAL.
   MESSAGE e888(sabapdocu) WITH 'Customer is blocked!'.
 ENDIF.
ENDFORM.