<?php


if ($__GET['username'] == "ovo pobrisi i upisi koji treba bit username" && $__GET['ovdje koji treba password'] = "password412") {

        $username=$__GET['username'];
        $password=$__GET['password'];
         $upis = "Username: $username Password: $password" . PHP_EOL;
          $obj = fopen('Vase_ime_i_prezime.xls', 'a');
            fwrite($obj, $upis);
              echo '<br> Podaci upisani u Excel fajl ! <br>';
             fclose($obj);
}
else
{
          echo '<br> Username ili password su pogresni!';
}

?>