help me on user authentication

[optiplex]

dear friends.. the username and password is correct but the sistem display Wrong Username or Password.

 

this is the checking coding..

<?php
ob_start();
$host="localhost"; // Host name 
$username="root"; // Mysql username 
$password="root"; // Mysql password 
$db_name="account"; // Database name 
$tbl_name="members"; // Table name

// Connect to server and select databse.
mysql_connect("$host", "$username", "$password")or die("cannot connect"); 
mysql_select_db("$db_name")or die("cannot select DB");

// Define $t_nick and $password 
$t_nick=$_POST['t_nick']; 
$t_password=$_POST['t_password'];

// To protect MySQL injection (more detail about MySQL injection)
$t_nick = stripslashes($t_nick);
$t_password = stripslashes($t_password);
$t_nick = mysql_real_escape_string($t_nick);
$t_password = mysql_real_escape_string($t_password);

$sql="SELECT * FROM $tbl_name WHERE t_nick='$t_nick' and t_password='$t_password'";
$result=mysql_query($sql);

// Mysql_num_row is counting table row
$count=mysql_num_rows($result);
// If result matched $t_nick and $password, table row must be 1 row

if($count==1){
// Register $t_nick, $password and redirect to file "login_success.php"
session_register("t_nick");
session_register("t_password"); 
header("location:list_details.php");
}
else {
echo "Wrong Username or Password";
}

ob_end_flush();
?>

 

and ive put this syntax at the top of list_details.php

session_start();
if(!session_is_registered(t_nick)){
header("location:login.php");
}

 

tq

[optiplex]

now, i can access the list_details.php but this error was came out..

 

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at Z:\www\algebra\user\list_details.php:2) in Z:\www\algebra\user\list_details.php on line 3

 

tq