세션ID: dmc7rfgo54ad8qkuv2ujumhm9a
session1:
Warning: Undefined array key "session1" in /users/2021/i2151021/public_html/2022/WebProg/ch10/exam10-05.php on line 11

session2:
Warning: Undefined array key "session2" in /users/2021/i2151021/public_html/2022/WebProg/ch10/exam10-05.php on line 12

session3:
Warning: Undefined array key "session3" in /users/2021/i2151021/public_html/2022/WebProg/ch10/exam10-05.php on line 13

세션설정
세션변수 session1 삭제
모든 세션변수 삭제
세션삭제