php中用数组的方法设置cookies

<?php
    functionset_cronology($name,$value,$duration=7){
        $duration=time()+(3600*24*$duration);
        $max_stored_values=5;
        if(isset($_COOKIE[$name])){
            foreach($_COOKIE[$name]as$prop_crono=>$val_crono){
                if($val_crono==$value)
                    return;
            }
            if($prop_crono<$max_stored_values)
                setcookie($name."[".($prop_crono+1)."]",$value,$duration);
            else{
                array_shift($_COOKIE[$name]);
                setcookie("$name[$max_stored_values]",$value,$duration);
            }
        }else
            setcookie($name."[0]",$value,$duration);
        return;
    }
?>