Birde 

foreach($_COOKIE as $key => $val){
       $$key= $val;
}
foreach($_SESSION as $key => $val){
       $$key= $val;
}
foreach($_POST as $key => $val){
       $$key= $val;
}
foreach($_GET as $key => $val){
       $$key= $val;
}
bu koddan $_COOKIE ve $_SESSION u kaldiralim

foreach($_POST as $key => $val){
       $$key= $val;
}
foreach($_GET as $key => $val){
       $$key= $val;
}
bu şekilde olsun yani, eskisini bununla değiştir