is there any function to find erros in php? [closed]

Notice: Undefined index: newsname 33

34Notice: Undefined index: news in

    $news = $newsname = "";

    $news = mysqli_real_escape_string($link,$_POST['newsname']);   //line 33
    $newsname = mysqli_real_escape_string($link,$_POST['news']);   //line 34

    $sql = "INSERT INTO news(news,newsname)
    VALUES('{$news},{$newsname}')";

    if (mysqli_multi_query($link,$sql)) {
      header("location: ../pages/news.php");
    }else{
      echo "<div class='alert alert-danger'>Query Failed</div>";
    }