Cannot modify header infomation - headers already sent.

[BittenApple]

Hi,

I'm having the below problem when I vote on a poll on a site..

Warning: Cannot modify header information - headers already sent by (output started at /header.php:77) in /poll/poll_cookie.php on line 21

You can still vote on it, its just this error comes up and streches the table If anyone can help that would be greatful..

If you wanted to know, its an RPG game, and theres alot of code in header.php and I hate problems with the sessions iswell before..

Also heres line twenty one :

        setcookie($cookie_name, "1", $endtime);

And if you wanted, heres the poll code:

<?php
$cookie_expire = 96; // hours

$action = (isset($HTTP_GET_VARS['action'])) ? $HTTP_GET_VARS['action'] : '';
$action = (isset($HTTP_POST_VARS['action'])) ? $HTTP_POST_VARS['action'] : $action;
$poll_ident = (isset($HTTP_GET_VARS['poll_ident'])) ? $HTTP_GET_VARS['poll_ident'] : '';
$poll_ident = (isset($HTTP_POST_VARS['poll_ident'])) ? $HTTP_POST_VARS['poll_ident'] : $poll_ident;

if ($action=="vote" && (isset($HTTP_POST_VARS['option_id']) || isset($HTTP_GET_VARS['option_id']))) {
    $cookie_name = "AdvancedPoll".$poll_ident;
    if (!isset($HTTP_COOKIE_VARS[$cookie_name])) {
        $endtime = time()+3600*$cookie_expire;
        setcookie($cookie_name, "1", $endtime);
    }
}
?>

[spikeZ]

The problem is on header.php line 77 not on this code!

[Krieger]

As spikeZ said - line 77.

Also - if nothing jumps out as an obvious problem try checking for whitespace. If whitespace is encountered (spaces, characters, carriage returns) the browser will interpret this as output and send the headers.

When I run into this it's usually an accidental carriage return at the end of an include file.

[shogan]

do you apply any html header to your php script.. because in my experience it can cause u that problem..

[devised]

You could put:

ob_start(); 

at the very top of the page, and then put:

ob_end_flush(); 

at the very end of the page to buffer the output.