$user="logicsequence";
$password="132435~~";
$dbname="logicsequence";

$mysqli = new mysqli('localhost', $user, $password, $dbname);

//save all the notes and hiddens
if($_POST['notes']==1){
    foreach ($_POST as $k => $a) {
        if($k!="notes"){
            if(!preg_match("/check/", $k)){
                $a = $mysqli->real_escape_string($a);
                $result = $mysqli->query("UPDATE `contacts` SET `notes`='$a', valid='1' WHERE `id`='$k'");
            }
            if(preg_match("/check/", $k)){
                $k=str_replace("check", "", $k);
                $result = $mysqli->query("UPDATE `contacts` SET `valid`='0' WHERE `id`='$k'");
            }
        }
    }
}