Na zaciatku uplnom ked napsies:
<?
session_start();
?>
Tak to znamena ze si ma server overit cookies, ci sedia, bez toho ti preklikavanie na inu stranku nebude fungovat...
A podmienka zo session je potom jednoducha - cize:
<?
include "db.php";

$s = mysql_query("Select * from side order by id desc");
while($e = mysql_fetch_array($s)):
//musime vybrat z databaze udaje, aby sme mali podla coho porovnat ci sa nachadza dany uzivatel v databazi
if ($e['autor'] == $_SESSION['login'])
{
echo "Blablabla som prihlaseny";
}
----------------------------------------------------------
V subore Checklogin.php je prihlasenie, vsimni si riadok kde je $myusername == session(login) ci take cosi, to urcuje co sa zapise do cookies... Takze podla toho sa potom odvija ta podmienka.. ak uz mas prihlasovanie proste si najdi podobny riadok, bude to tam.
Checklogin.php
----------------------------------------------------------
<?
session_start();
?>
<?php
$host="localhost"; // Host name
$username="artofsurvival_hy"; // Mysql username
$password="pk4life"; // Mysql password
$db_name="artofsurvival_hy"; // 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");

// username and password sent from form
$myusername=$_POST['myusername'];
$mypassword=$_POST['mypassword'];

// To protect MySQL injection (more detail about MySQL injection)
$myusername = stripslashes($myusername);
$mypassword = stripslashes($mypassword);
$myusername = mysql_real_escape_string($myusername);
$mypassword = mysql_real_escape_string($mypassword);

$sql="SELECT * FROM $tbl_name WHERE username='$myusername' and password='$mypassword'";
$result=mysql_query($sql);

// Mysql_num_row is counting table row
$count=mysql_num_rows($result);
// If result matched $myusername and $mypassword, table row must be 1 row
if($count==1){
// Register $myusername, $mypassword and redirect to file "login_success.php"
$_SESSION['login']=$myusername;
header("location:index.php");
}
else {
echo "Wrong Username or Password";
}
?>