<?php
				$conn = mysqli_connect('localhost','root','','biblio');
				if (isset($_POST['see'])) {
					$zapytanie = "SELECT tytul, cena FROM ksiazka WHERE cena > 50 AND lstron < 300";
					$query = mysqli_query($conn,$zapytanie);

					while ($row = mysqli_fetch_array($query)){
						echo "<p>tytul: ".$row['tytul']."<br>"." cena: ".$row['cena']."</p>";
					}
				}
				mysqli_close($conn);
			?>