function odeslat_mail($pro,$predmet,$text) {
  $mail_from = "mail@odesilatele.cz";

  if(!empty($od)) { $mail_from = $od; }
  $headers  = "";
  $headers .= "X-Sender: ".$mail_from."\n"; //
  $headers .= "From: ".$mail_from."\n";
  $headers .= "Reply-To: ".$mail_from."\n";
  $headers .= "Date: ".date("r")."\n";
  $headers .= "Message-ID: <".date("YmdHis")."".$mail_from.">\n";
  $headers .= "Return-Path: ".$mail_from."\n";
  $headers .= "Delivered-to: ".$mail_from."\n";
  $headers .= "MIME-Version: 1.0\n";
  $headers .= "Content-Type: text/plain; charset=utf-8\n";
  $headers .= "X-Priority: 3\n";
  $headers .= "Importance: Normal\n";
  $headers .= "X-MSMail-Priority: Normal\n";
  $headers .= "X-MimeOLE: Normal\n";
  $headers .= "X-Mailer: HostForum\n";
  $res = @mail($pro, $predmet, $text, $headers); unset($headers);
  return $res;
}