The error comes from having output before the session_start(). This
means that anything before the <? would be output. Even a single empty
space.
Janet
Humani Power wrote:
Hi! Im trying to make a login page. I have searched for examples that makes
me check the user name with a database, and the one that suits better is
this code.
<?
session_start(); // start session.
?>
<!-- header tags, edit to match your own, or include template header
file. -->
<html>
<head>
<title>Login</title>
<head>
<body>
<?
if(!isset($username) | !isset($password)) {
// escape from php mode.
?>
<form action="<?=$PHP_SELF?><?if($QUERY_STRING){ echo"?".
$QUERY_STRING;}?>" method="POST">
<p align="center">Members only. Please login to access this document.</p>
<table align="center" border="0">
<tr>
<th>
Username:
</th>
<th>
<input type="text" name="username">
</th>
</tr>
<tr>
<th>
Password:
</th>
<th>
<input type="password" name="password">
</th>
</tr>
<tr>
<th colspan="2" align="right">
<input type="submit" value="Login">
</form>
</th>
</tr>
</table>
</body>
</html>
<?
exit();
}
// If all is well so far.
session_register("username");
session_register("password"); // register username and password as
session variables.
// Here you would check the supplied username and password against
your database to see if they exist.
// For example, a MySQL Query, your method may differ.
$sql = mysql_query("SELECT password FROM user_table WHERE username =
'$username'");
$fetch_em = mysql_fetch_array($sql);
$numrows = mysql_num_rows($sql);
if($numrows != "0" & $password == $fetch_em["password"]) {
$valid_user = 1;
}
else {
$valid_user = 0;
}
// If the username exists and pass is correct, don't pop up the login
code again.
// If info can't be found or verified....
if (!($valid_user))
{
session_unset(); // Unset session variables.
session_destroy(); // End Session we created earlier.
// escape from php mode.
?>
<form action="<?=$PHP_SELF?><?if($QUERY_STRING){ echo"?".
$QUERY_STRING;}?>" method="POST">
<p align="center">Incorrect login information, please try again. You
must login to access this document.</p>
<table align="center" border="0">
<tr>
<th>
Username:
</th>
<th>
<input type="text" name="username">
</th>
</tr>
<tr>
<th>
Password:
</th>
<th>
<input type="password" name="password">
</th>
</tr>
<tr>
<th colspan="2" align="right">
<input type="submit" value="Login">
</form>
</th>
</tr>
</table>
</body>
</html>
<?
exit();
}
?>
After this, I have only included on a file that has this code
<?php
include_once 'connection/login.php';
?>
But when I try to see it in a browser I got the error
*Warning*: session_start() [function.session-start
<http://localhost/apache2-default/function.session-start>]: Cannot
send session cache limiter - headers already sent (output started at
/var/www/apache2-default/visual_imag.php:2) in
*/var/www/apache2-default/connection/login.php* on line *2
I have searched for possible answers, and all I have found is that I
should not send any output before the session_start(); But in this
code the session_start(); output is before anything else.
can you give me a tip?
Thanks in advance.
Yamil
*
--
Janet Valade -- janet.valade.com
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