Salve a tutti,

avevo gia fatto una cosa del genere tempo fa e funzionava ora non riesco a risolvere, praticamente ho un css mastercss.php composto cosi:

Codice PHP:
<?php 
header('Content-type: text/css');
?>
<style type="text/css">
a:link {
    color: #FFCC00;
    text-decoration: none;
}
a:visited {
    color: #FF0000;
    text-decoration: none;
}
a:hover {
    color: #FF6600;
    text-decoration: none;
}
a:active {
    color: #FFCC00;
    text-decoration: none;
}

body {
    background-color: #000000;
}
.TitoloLogin {
    font-family: Verdana, Arial, Helvetica, sans-serif;
    font-size: 18px;
    color: #FF9900;
    text-decoration: none;
}
.TestoLogin {
    font-family: Verdana, Arial, Helvetica, sans-serif;
    font-size: 12px;
    text-decoration: none;
    color: #FFCC00;
}
.TestoTitoli {
    font-family: Verdana, Arial, Helvetica, sans-serif;
    font-size: 12px;
    color: #FFCC33;
}

.BoxStyle {
    font-family: Verdana, Arial, Helvetica, sans-serif;
    font-size: 12px;
    color: #FF9900;
    text-decoration: none;
    background-color: #666666;
    padding: 1px;
    border-top-style: none;
    border-right-style: none;
    border-bottom-style: none;
    border-left-style: none;
}
.Cinv {
    font-family: Verdana, Arial, Helvetica, sans-serif;
    color: #000000;
}
.TestoIndicativo {
    font-family: Verdana, Arial, Helvetica, sans-serif;
    font-size: 12px;
    text-decoration: none;
    color: #FFCC00;
}
.ContornoBordo {
    border: 1px dashed #FF6600;
}
</style>
voglio includerlo in una pagina ma mi da sempre un messggio di errore:

Warning: Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\tsl-tools\index.php:26) in C:\xampp\htdocs\tsl-tools\css\master.php on line 2

La pagina index.php

Codice PHP:
<?php
error_reporting (E_ALL);
session_start();
if(isset($_GET['action']) && $_GET['action'] == "LoginFail") {
    $msg = "Login errato riprova";
}
if(isset($_GET['action']) && $_GET['action'] == "LogOut") {
    $msg = "Logout effettuato con successo";
}
if(isset($_GET['action']) && $_GET['action'] == "Timeout") {
    $msg = "Sessione scaduta!!";
}
if(isset($_POST['Submit']) && $_GET['action'] == "Login") {
include"config.inc.php";
include"function.inc.php";
$user = (trim(mysql_escape_string($_POST['usr'])));
$pass = (trim(mysql_escape_string($_POST['pwd'])));
checkLogin($user, $pass);
} 
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
<?php include"css/master.php";?> **********riga 26***********
</head>
So che deve essere prima di ogni output ma non riesco a capire!!!!

Qualcuno mi da una mano gentilmente!

Grazie Michel