Authoring Code

  var isIE = navigator.appVersion.indexOf("MSIE")>0
  var isNav = navigator.appVersion.indexOf("Nav")>0
  var isIE4 = isIE && version>=4
  var isNav4 = isNav && version>=4

  if (isIE4) {
    document.write("<H2 align=center>Internet Explorer 4.0</H2>")
  }
  else
    if (isNav4) {
      document.write("<H2 align=center>Netscape Navigator 4.0</H2>")
    }
    else {
      document.write("<H2 align=center>Other Browser</H2>")
    }