세션ID: uepqb85reepijallejjifvntua
session1:
Warning: Undefined array key "session1" in /users/2021/i2151059/public_html/2022/WebProg/ch10/exam10-08.php on line 13

session2:
Warning: Undefined array key "session2" in /users/2021/i2151059/public_html/2022/WebProg/ch10/exam10-08.php on line 14

session3:
Warning: Undefined array key "session3" in /users/2021/i2151059/public_html/2022/WebProg/ch10/exam10-08.php on line 15

세션확인
세션변수 session1 삭제
모든세션변수삭제
세션삭제