warning ved session

Jeg er lige begyndt at benytte session i php og har lavet en lille test som ser sådan her ud :

<?php
  session_start();
 
  $HTTP_SESSION_VARS['sess_var'] = "Hello world!";

  echo 'The content of $HTTP_SESSION_VARS[\'sess_var\'] is '
        .$HTTP_SESSION_VARS['sess_var'].'<br />';
?>
<a href="page2.php">Next page</a>


Men den melder følgende :



Warning: session_start(): open(/tmp\sess_2897911312c3f9e5bd0d086916965e8e, O_RDWR) failed: No such file or directory (2) in c:\apache\apache\htdocs\page1.php on line 2

Warning: session_start(): Cannot send session cookie - headers already sent by (output started at c:\apache\apache\htdocs\page1.php:2) in c:\apache\apache\htdocs\page1.php on line 2

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at c:\apache\apache\htdocs\page1.php:2) in c:\apache\apache\htdocs\page1.php on line 2
The content of $HTTP_SESSION_VARS['sess_var'] is Hello world!
Next page
Warning: Unknown(): open(/tmp\sess_2897911312c3f9e5bd0d086916965e8e, O_RDWR) failed: No such file or directory (2) in Unknown on line 0

Warning: Unknown(): Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in Unknown on line 0



Da det er fra en bog jeg har kopieret det kan jeg ikke forstå at der er fejl?????