function BrowserIn() {
  var s, i, ua;

  ua = navigator.userAgent;
  this.isIE    = false;
  this.isNS    = false;
  this.isFF    = false;
  this.isOpera = false;
  this.version = null;

  this.minIE = 5;
  this.minNS = 7;
  this.minFF = 1;
  this.minOpera = 8;

  this.goodIE = 5.5;
  this.goodNS = 7;
  this.goodFF = 1;
  this.goodOpera = 7;

  if (window.opera) {
    this.isOpera = true;

    if ((i = ua.indexOf(s = "Opera/")) >= 0)
      this.version = parseFloat(ua.substr(i + s.length));
    else if ((i = ua.indexOf(s = "Opera")) >= 0)
      this.version = parseFloat(ua.substr(i + s.length));

    return;
  }
  else {
    s = "MSIE";
    if ((i = ua.indexOf(s)) >= 0) {
      this.isIE = true;
      this.version = parseFloat(ua.substr(i + s.length));
      return;
    }

    s = "Netscape6/";
    if ((i = ua.indexOf(s)) >= 0) {
      this.isNS = true;
      this.version = parseFloat(ua.substr(i + s.length));
      return;
    }

    s = "Netscape/";
    if ((i = ua.indexOf(s)) >= 0) {
      this.isNS = true;
      this.version = parseFloat(ua.substr(i + s.length));
      return;
    }

    s = "Firefox/";
    if ((i = ua.indexOf(s)) >= 0) {
      this.isFF = true;
      this.version = parseFloat(ua.substr(i + s.length));
      return;
    }

    if (navigator.product == "Gecko") {
      this.isNS = true;
      this.version = (parseInt(navigator.productSub) > 20020800 ? 7 : 5);
      return;
    }

    this.isNS = true;
    this.version = 7;
    return;
  }
};

BrowserIn.prototype.oldVersionDisclaimer = function() {
  if (this.isIE)
    document.write("Please, update your Internet Explorer up to " + this.minIE + ".x or higher");
  else if (this.isNS)
    document.write("Please, update your NetScape Navigator up to " + this.minNS + ".x or higher");
  else if (this.isFF)
    document.write("Please, update your Firefox up to " + this.minFF + ".x or higher");
  else if (this.isOpera)
    document.write("Please, update your Opera up to " + this.minOpera + ".x or higher");
};

BrowserIn.prototype.goodVersionDisclaimer = function() {
  var Msg = "";
  if (this.isIE && this.version < this.goodIE)
    Msg = "�������� � ������ �������������. ����������, �������� ������ ������ Internet Explorer �� " + this.goodIE + " ��� ����";
  return Msg;
};

var browserIn = new BrowserIn();