Is there anything wrong with this code?

[vietfancy]

is there anything wrong with this code, if there is please point it out for me. Thanks

PHP Code:

   if (isset($_POST["submit"])){
    $id=$_POST["id"];
    $day=$_POST["day"];
    $time=$_POST["time"];
    $ampm=$_POST["ampm"];
    $class=$_POST["class"];
    $level=$_POST["level"];
    $instructor=$_POST["instructor"];
    $link=$_POST["link"];
    $display=$_REQUEST["display"];
    $live=$_POST["live"];
      //replace classes

    $db->query_write("UPDATE " . TABLE_PREFIX . "schedule SET day = $day, time = $time, ampm = $ampm, class = $class, level = $level, instructor = $instructor, link = $link, display = $display, live = $live WHERE id=$id")or die(mysql_error());
         $done = "Schedule updated";
         header("location: index.php?do=submit");
    }