if(isset($_POST['sponsorcode']) && !empty($_POST["sponsorcode"])){
   $sponsorcode = mysqli_real_escape_string($link,$_POST['sponsorcode']);
   $query = "SELECT 'sponsorcode' FROM 'teachercodes' WHERE sponsorcode = '$sponsorcode'";
   $result = mysqli_query($link, $query) or die(mysqli_error($link));
   $option = "";
   if(mysqli_num_rows($result)>0){
       while($row=mysqli_fetch_array($result)) {
       $option = "<option value='{$row['codes']}'>{$row['codes']}</option>";
}