Can't add variable into php session - php

Question

I am trying to add variable into session and read that variable in function.
so here is index.php:
<?php
include("include/config.php");
if(!empty($txt_user) && !empty($txt_pass))
{
$result=login_func($txt_user,$txt_pass);
if($result==1)
{
header("Location: homepage.php");
}else{
$alert_class="alert-danger";
}
}
?>
<form action="<?php echo("".$_SERVER['PHP_SELF']."");?>" method='post' class='form-validate' id="test">
<div class="form-group">
<div class="email controls">
<input type="text" name='txt_user' placeholder="Kullanıcı Adınız" class='form-control' data-rule-required="true">
</div>
</div>
<div class="form-group">
<div class="pw controls">
<input type="password" name="txt_pass" placeholder="Şifreniz" class='form-control' data-rule-required="true">
</div>
</div>
<div class="submit">
<input type="submit" value="Giriş Yap" class='btn btn-primary'>
</div>
</form>
config.php:
<?php
ini_set('session.gc_maxlifetime', 3600);
session_start();
ob_start();
include("class.php");
include("functions.php");
**connections to db**
?>
functions.php:
function login_func($user,$pass)
{
$sql=mysql_query("SELECT * FROM table WHERE user_name='$user' AND pass='$pass' LIMIT 1");
$control_number=mysql_num_rows($sql);
if(($control_number==1))
{
$_SESSION['login_id']=#mysql_result($sql,0,'id');
$_SESSION['login_name']=#mysql_result($sql,0,'name');
$_SESSION['login_email']=#mysql_result($sql,0,'email');
return 1; // true
}else{
return 2; //false
}
}
So if i add following commands to homepage.php i get empty result for each echo:
echo $_SESSION['login_id'];
echo $_SESSION['login_name'];
echo $_SESSION['login_email'];
even also if i do same echo action just in function it doesnt give any output too.
So i am stuck on here and cant find what cause this problem. thanks for your helps.
please dont worry about syntax errors I think that only problem is using wrong sessions and sessions conf.

Answer 1

You are trying to access $txt_user and $txt_pass variables as registered globals.
Unless you are using php 5.3 and below the register_globals is removed from PHP.
Registering globals is a huge security risk and should be avoided in any case.
Try using $_POST['txt_user'] and $_POST['txt_pass'] instead