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// create session cookie
session_start();

if (!isset($_SESSION['session']) || !isset($_SESSION['token']))
{
	// this variable is to make sure we get post from correct form
	// we will add it to every form as a hidden field
	$_SESSION['token'] = uniqid(md5(microtime()), true); 
	// this is for making it harder to hijack one's session cookie 
	// save ip and user agent which created the session
	$_SESSION['session'] = md5($_SERVER['REMOTE_ADDR'] . $_SERVER['HTTP_USER_AGENT']); 
}