(function () {
  'use strict';

  function emulatediemajorversion() {
    var groups = /msie ([0-9.]+)/.exec(window.navigator.useragent)
    if (groups === null) {
      return null
    }
    var ieversionnum = parseint(groups[1], 10)
    var iemajorversion = math.floor(ieversionnum)
    return iemajorversion
  }

  function actualnonemulatediemajorversion() {
   
    var jscriptversion = new function('/*@cc_on return @_jscript_version; @*/')() // jshint ignore:line
    if (jscriptversion === undefined) {
      return 11 // ie11+ not in emulation mode
    }
    if (jscriptversion < 9) {
      return 8 // ie8 (or lower; haven't tested on ie<8)
    }
    return jscriptversion // ie9 or ie10 in any mode, or ie11 in non-ie11 mode
  }

  var ua = window.navigator.useragent
  if (ua.indexof('opera') > -1 || ua.indexof('presto') > -1) {
    return // opera, which might pretend to be ie
  }
  var emulated = emulatediemajorversion()
  if (emulated === null) {
    return // not ie
  }
  var nonemulated = actualnonemulatediemajorversion()

  if (emulated !== nonemulated) {
    window.alert('warning: you appear to be using ie' + nonemulated + ' in ie' + emulated + ' emulation mode.\nie emulation modes can behave significantly differently from actual older versions of ie.\nplease don\'t file bootstrap bugs based on testing in ie emulation modes!')
  }
})();