       IDENTIFICATION DIVISION.
       PROGRAM-ID. ADDRBOOK.

       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 WS-CONTACT.
          05 CONTACT-ID        PIC 9(8).
          05 CONTACT-NAME      PIC X(50).
          COPY ADDRESS.
          05 CONTACT-PHONE     PIC X(15).

       LINKAGE SECTION.
       01 LK-CONTACT-ID        PIC 9(8).
       01 LK-FOUND-FLAG        PIC X(1).

       PROCEDURE DIVISION USING LK-CONTACT-ID LK-FOUND-FLAG.
       LOOKUP-CONTACT.
           MOVE 'N' TO LK-FOUND-FLAG.
           GOBACK.
