while($row = $result->fetch_assoc()) {
    echo "<tr>";
    echo "<td>" . $row["nr"]. "</td>";
    echo '<td><form method="post"><input type="text" value="' . $row["name"]. '" name="nametochange"/></form></td>';

    }
echo    "</table>";
    echo '<form method="post"><input type="submit" name="OkEditAction" id="'. $ID.'" value="OK" /><input type="hidden" value="'.$ID.'" name="OkEdit2"/></form>';
    echo '<form method="post"><input type="submit" name="NotOkEditAction" id="'. $ID.'" value="Anuluj" /><input type="hidden" value="'.$ID.'" name="OkEdit3"/></form>';


} else {
    echo "0 results";
}
$conn->close();

}


function OkEditAction()
{

echo "</table>";
$ID = $_POST['OkEdit2'];
$imiedozmiany = $_POST['nametochange'];
$servername = "localhost";
$username = xxx;
$password = xxx;
$dbname = xxx;

header('Content-Type: charset=UTF-8');

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);

// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

else

{
echo $ID;
$sql = "UPDATE zlecenia SET name ='". $imiedozmiany."' WHERE nr=". $ID;
echo $sql;
$result = $conn->query($sql);