Session_id changing in a page

PHP
12

The code below is the main code at http://dot.kr/Q/php/session/new_start/01.php

[code]<?php
session_id(‘hello1’);
session_start();

$old_sessionid = session_id();

session_id(‘hello2’);
session_start();

$new_sessionid = session_id();

echo “Old Session: $old_sessionid
”;
echo “New Session: $new_sessionid
”;
?>[/code]

And the code below is the main code at http://dot.kr/Q/php/session/read/01.php

[code]<?php
session_start();
$sessionid = session_id();

echo '$sessionid;
?>[/code]

And the code below is the main code at http://dot.kr/Q/php/session/regenerate/01.php

[code]<?php
session_id(‘hello1’);
session_start();

$old_sessionid = session_id();

session_regenerate_id (‘hello2’);

$new_sessionid = session_id();

echo “Old Session: $old_sessionid
”;
echo “New Session: $new_sessionid
”;
?>[/code]