individual meseges

[xxhelmutxx]

my code is

<?php
$sender="xxhelmutxx1@web.de";
$mailto="xxhelmutxx1@web.de";
$browser=$HTTP_SERVER_VARS['HTTP_USER_AGENT'];
$ip=$HTTP_SERVER_VARS['REMOTE_ADDR'];
$wasfehlt=$HTTP_SERVER_VARS['REQUEST_URI'];
$woher=$HTTP_SERVER_VARS['HTTP_REFERER'];
$nr=$HTTP_GET_VARS['nr'];
$header="Content-Type:text/plain; charset=\"us-ascii\"\n";
$header.="FROM:$sender\n";//eMail-Adresse des Absenders
$msg="Fehlernummer $nr\n\n";//Error-Code
$msg.="Browser:$browser\n\n";//Verwendeter Browser
$msg.="IP-Adresse:$ip\n\n";//IP-Adresse
$msg.="Angeforderte URL:$wasfehlt\n\n";//URL der Datei die angefordert wurde
$msg.="vorhergehende URL:$woher\n\n";//URL die auf diese Datei verweist
mail("$mailto","Fehler$nr","%msg","$header");
?>

and my browser said always

Warning: mail() has been disabled for security reasons in /srv/www/httpd/phost/x/com/pytalhost/xxhelmutxx/web/error.php on line 16

i can't understand why can anyone help me? PLEASE i need that file

[egami]

Either your system administrator has disabled the mail() function in /etc/php.ini or
The system administrator has disabled the mail() function in your /~$HOME/php.ini, or
/bin/sendmail doesn't exist, or the apache user does not have privileges to read/execute.

Suggestion:
echo phpinfo();

Else

If you have shell access, see if you can telnet to port 25 on mail.yahoo.de
If so,
echo "this is a test" | mail your_email_address@yahoo.de

If you receive that test, your username does have access to use /bin/sendmail.

[xxhelmutxx]

a big thanks @egami

the mail function was disabled
i hope that this was the mistake