Warning: Cannot modify header information

[PHPiSean]

I get an error stating that I cannot modify header information when I try to add a title to my login page.

Here's

<?php
session_start();

require_once("includes/dbconn.php");

include("includes/htmlheader.php");

mysql_select_db(center);

$user = $_POST['username'];
$pass = $_POST['password'];

$sql = "select username, password from users";
$result = mysql_query($sql);
$row = mysql_fetch_array($result);

$isuser = $row['username'];
$ispass = $row['password'];

if(isset($_POST['submit'])){
if(($user==$isuser)&&($pass==$ispass)) {
$_SESSION['username'] = $user;
header("Location: home.php");
    }else{
    echo "Invalid Username or Password";
    }
}

   
?>

 

The htmlheader.php has the title string. Help is appreciated 

[KevinM1]

Our first thread in this subforum deals with exactly this: http://www.phpfreaks.com/forums/php-coding-help/header-errors-read-here-before-posting-them/

[PFMaBiSmAd]

The error message, that you didn't post, tells you where the output is occurring at that is preventing the header() from working.

 

I'll guess it was a line in the htmlheader.php file? You cannot output any characters to the browser before you use a header() statement and if you are going to redirect the browser, there's no point in outputting anything, even if it did work.