Warning: session_start() [function.session-start]: open(/var/lib/php5/sess_46fe65357b2e96192181d8afdbda68e3, O_RDWR) failed: No such file or directory (2) in /captcha.php on line 2

Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /captcha.php:2) in /captcha.php on line 2

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /captcha.php:2) in /captcha.php on line 2

Warning: Cannot modify header information - headers already sent by (output started at /captcha.php:2) in /captcha.php on line 3

Warning: imagecreatefrompng(captcha.png) [function.imagecreatefrompng]: failed to open stream: No such file or directory in /captcha.php on line 4
Cannot Initialize new GD image stream
Warning: Unknown: open(/var/lib/php5/sess_46fe65357b2e96192181d8afdbda68e3, 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 (/var/lib/php5) in Unknown on line 0