<?php
$islogin = false;
if (isset($_GET["kod"]) && $_GET["kod"] == 1111 ) {
echo "Üdvözöllek".$_GET["nev"];
$islogin = true;
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>PHP form</title>
</head>
<body>
<?php
if ($islogin == "false") {
?>
<form>
<input type="text" name="nev" title="Adja meg a nevet"><br>
<input type="number" name="kod" min="1000" max="5000" title="Adja meg a kódot"><br>
<input type="submit" value="Belépés">
</form>
<?php
}
?>
</body>
</html>