<?php
/**
   * Функция определения браузера пользователя
   * @version 0.1
   * @author recens
   * @license GPL
   * @copyright Гельтищева Нина (http://recens.ru)
   */

function user_browser($agent) {
   preg_match("/(MSIE|Opera|Firefox|Chrome|Version|Opera Mini|Netscape|Konqueror|SeaMonkey|Camino|Minefield|Iceweasel|K-Meleon|Maxthon)(?:\/| )([0-9.]+)/", $agent, $browser_info);
   list(,$browser,$version) = $browser_info;
   if (preg_match("/Opera ([0-9.]+)/i", $agent, $opera)) return 'Opera '.$opera[1];
   if ($browser == 'MSIE') {
    preg_match("/(Maxthon|Avant Browser|MyIE2)/i", $agent, $ie);
    if ($ie) return $ie[1].' based on IE '.$version;
    return 'IE '.$version;
   }
      if ($browser == 'Firefox') {
    preg_match("/(Flock|Navigator|Epiphany)\/([0-9.]+)/", $agent, $ff);
    if ($ff) return $ff[1].' '.$ff[2];
   }
   if ($browser == 'Opera' && $version == '9.80') return 'Opera '.substr($agent,-5);
   if ($browser == 'Version') return 'Safari '.$version;
   if (!$browser && strpos($agent, 'Gecko')) return 'Browser based on Gecko';
   return $browser.' '.$version;
}

function user_min_browser($agent) {
   preg_match("/(MSIE|Opera|Firefox|Chrome|Version)(?:\/| )([0-9.]+)/", $agent, $browser_info);
   list(,$browser,$version) = $browser_info;
   if ($browser == 'Opera' && $version == '9.80') return 'Opera '.substr($agent,-5);
   if ($browser == 'Version') return 'Safari '.$version;
   if (!$browser && strpos($agent, 'Gecko')) return 'Browser based on Gecko';
   return $browser.' '.$version;
}
?>

<form action="/php/script.php"><input type="text" name="text"><input type="submit" value="Отправить"></form>

$_POST['text']