switch ($tip)
{ 
  case "perakende":
   setcookie("Tip", 'perakende', '/');
   break;
  case "toptan":
  setcookie("Tip", 'toptan', '/')
  break;
  default:
  setcookie('Tip', 'NULL', '/'); 
}

switch ($_COOKIE["TestCookie"]){
case 'perakende':
include ("parakendeUrunler.php");
break;
case 'toptan':
include ("toptanUrunler.php");
break;
case default:
include ("Urunler.php");
break;
}