session_set_cookie_params(0, '/', '.domain.com');
session_start();
if(isset($_SESSION["isauth"]) && $_SESSION["isauth"] == true)
{
  $result = mysql_query("SELECT * FROM users WHERE id='$_SESSION[uid]'");
  $user = mysql_fetch_array($result);
}
else
  $user = 0;

session_start();
$_SESSION["isauth"] = true;
$result = mysql_query("SELECT id FROM users WHERE email='$email' AND password='$password'");
$uid = mysql_fetch_array($result);
$_SESSION["uid"]=$uid[0];