Need help with error message

[engrsapper42]

I made a slide show with images that link to the description. When i click on the image, the page goes to the discription but I get this error message on top of the page.

 

Warning: session_start(): The session id contains invalid characters, valid characters are only a-z, A-Z and 0-9 in /home/ucybersh/public_html/osCommerce/catalog/includes/functions/sessions.php on line 67

 

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/ucybersh/public_html/osCommerce/catalog/includes/functions/sessions.php:67) in /home/ucybersh/public_html/osCommerce/catalog/includes/functions/sessions.php on line 67

 

I dont know how to get rid of it.

Please help.

Thank you

Luis