erorr in php code

[Anon]

i am making now greeting card script
after the user entering the data
from :
to :

and when the script sending the email to the user to notify that he have greeting card
i had this erorr

Warning: Cannot add header information - headers already sent by (output started at c:\phpdev2\www\q8group\choose-card.php:8) in mailform.php on line 12
and the email sent but the script doesn't go to the thank page
this is the code of mail system

function send_mail_to_card()
{
mail($email_to, $subject, $bodysend,
"From : " . $email_from);
header ("Location : $mailfrom_url");
}
?>

and when i wanna send email i just type
send_mail_to_card()

so any one can help ?

[gljaber]

just make sure that there is absoloutley no output to the browser before the call to header.

Not even a print(""), or a html comment or anything.

glj