PHP header error message

[Anon]

I put the following code in my html document:

<?php
include("stylesheet.txt");
$expires = time()[phone];
if (!isset($cooks))
{
setcookie("cooks","yes",$expires);
echo "<script language=\"Javascript\">window.open(feature.html','Terms','width=430,height=400,scrollbars=yes');</script>";
}
?>

It includes the style sheet and pops up the window, but I get the following error message:

Warning: Cannot add header information - headers already sent by (output started at /www/virtual-cards/test/index.php3:6) in www/virtual-cards/test/index.php3on line 18

Please help!

[Anon]

When you include stylesheet.txt, its text is inserted at that very point in the page. So when you call setcookie(), there has already been output, and it is too late to write to the headers. Cookies can only be sent before any other output, they just work like that.

So if you move the include() line down a bit, below the setcookie(), it should work.

[Anon]

You can't write any words , HTML tags or Javascript before send header.
Notice the include file "stylesheet.txt",