[PHP] PHP Session song...

I get that error when i try to start a session. Warning: Cannot send session cookie - headers already sent by (output started at What is happen? Germán Pablo Gentile IT Manager Horizonte Soluciones de IT www.horizonteit.com.ar [EMAIL PROTECTED] -- PHP General Mailing List

[PHP] POST and trouble.

I´m using post to send a variable between pages. I have a variable value like that 'JeffCompany', so i have in the header : loginok.php?client_id=14client_name=JeffCompany Loginok page take the value at client_name as Jeff. Truncate the real value. How in can fix that? Thanks in advance.