<form method="POST" action="<?php echo $_SERVER['PHP_SELF'];?>">
<input type="textfield" name="pitanje" value="Unesi pitanje"/> <br>
<input type="textfield" name="odgovor" value = "Unesi odgovor"/><br>
<input type="textfield" name="poeni" value="Unesi broj poena"/><br>
<input type="submit" name="submit" value="Posalji" /><br>
</form>
<?php
if (isset($_POST['submit']))
{
    $link = mysqli_connect("127.0.0.1","root","","kviz");
    $q1 = mysqli_query ($link, "INSERT INTO pitanja (`id`, `tekst_pitanja`, `odgovor`, `broj_poena`) VALUES ('', '".$_POST['pitanje']."', '".$_POST['odgovor']."', '".$_POST['poeni']."')");
    echo "Uspesno ste uneli pitanje.";
    mysqli_close($link);
}

?>