var ps = Components. classes ["@mozilla.org/preferences-service;1"]. getService (Components. interfaces. nsIPrefService). getBranch ("general.");
    ps. setCharPref ("useragent.override", "reset");

this.PS = Components.classes['@mozilla.org/preferences-service;1'] .getService(Components.interfaces.nsIPrefBranch);
this.PS.clearUserPref("general.useragent.override");
this.image=
'data:image/x-icon;base64,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';


var меню =
'<menupopup xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"\n\
       oncommand="this.parentNode.сменитьЮзерагент(event)">\n\
          <menuitem type="radio" value="reset" label="Default"/>\n\
          <menuseparator/>\n\
    <menuitem type="radio" value="Mozilla/5.0 (iPhone; CPU iPhone OS 10_0 like Mac OS X) AppleWebKit/602.1.50 (KHTML, like Gecko) News/582.1 Version/2.0" label="iPhone"/>\n\
    </menupopup>';


меню = e4xConv_parseXULFromString (меню);
меню. childNodes [0]. setAttribute ("checked", "true");
this. orient = "horizontal";
this. type = "menu";
this. appendChild (меню);
this. сменитьЮзерагент = function (событие)
{
    var юзерагент = событие. target. getAttribute ("value");
       var ps = Components. classes ["@mozilla.org/preferences-service;1"]. getService (Components. interfaces. nsIPrefService). getBranch ("general.");
    ps. setCharPref ("useragent.override", юзерагент);
this.PS = Components.classes['@mozilla.org/preferences-service;1'] .getService(Components.interfaces.nsIPrefBranch);
this.pref='general.useragent.override';
var state=this.PS.getCharPref(this.pref);
if (state=="reset") { 
this.PS = Components.classes['@mozilla.org/preferences-service;1'] .getService(Components.interfaces.nsIPrefBranch);
this.pref='general.useragent.override';
var state=this.PS.getCharPref(this.pref);
this.PS = Components.classes['@mozilla.org/preferences-service;1'] .getService(Components.interfaces.nsIPrefBranch);
this.PS.clearUserPref("general.useragent.override"); 
this.image=
'data:image/x-icon;base64,AAABAAEAEBAAAAEAIABoBAAAFgAAACgAAAAQAAAAIAAAAAEAIAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAD///8A////AJkyAACZMwAAmTIAAJcwAACUKQBAqVIh1J48CX6YMAAAmTMAAJkzAACZMwAAmDEAAP///wD///8A////AP///wCZMgAAmTMAAJQqABadNwiRz45Y+fTUo/+fPgyKlSoAAJcvAACZMgAAmTMAAJgxAAD///8A////AP///wD///8Aly8AAZUvAV65Xyji8LBn///XiP/6xoD/r1wq56hRIcmkSxm7ljEBcZcwAAeZMQAA////AP///wD///8A////AKFCEcfhkkn//7VY//+vUP//qEn//7BY//+5Yv//uF7//LVd/92NQ/+fPAq4li8AC////wD///8A////AP///wCdOQiLyGYe8vieP///rkz//6ZE//6nS//vkTj/7Ywz//qcPf//tFD/4og3/5gwAIb///8A////AP///wD///8AmDEAAJMrACikQQ2w2o9J///RgP/8xHn/oD4LyZYvAYmjPwzH8bNn///Zh/+0WiDn////AP///wD///8A////AJkyAACZMgAAli4AAJQrAFa3ZjDb5rp9/6JCDoqXLgAAkykALbhoMf/Wpmr/sVsl/////wD///8A////AP///wCZMwAAmTMAAJkzAACZMgAAlCsAEZo3BIiaNAFPmTMAAJo0AAeWLgBGkykASpcwAEX///8A////AP///wD///8AmDEAU5QqAFmWLgBXmjQADJkzAACaNQJJnj0Km5QqAB+ZMQAAmTMAAJkzAACZMwAA////AP///wD///8A////ALBZI//dr3H/wHU9/5IpAECWLgAAnjsIeem9gP/Bdz7qli8BbZUtAAOZMgAAmTIAAP///wD///8A////AP///wCtUBff/858//e6a/+qSRLYmTIEmaA9CMr3um///9J//+ObUf+rShPFkysAPJcwAAD///8A////AP///wD///8AlS4Acth8L///tE///6E///OSNv/0lTn//qVJ//+jQP//q0j//aNB/9JyJf2fPQug////AP///wD///8A////AJcvAAObNgaf1II9//eyXv/+tmD//rdj//+zXf//q0z//7JU//+1Wf/fkUn/okMSv////wD///8A////AP///wCYMAAAmDEAAJUuAFugQxKqpEoauqhRINz2xID//9qM/+6vZ/+2XCXelC4AWZcwAAD///8A////AP///wD///8AmDAAAJkzAACZMwAAlzAAAJYsAACcOAZ47sub/8yLVvWbNQaKlCsAEpkyAACZMwAA////AP///wD///8A////AJgwAACZMwAAmTMAAJkzAACYMQAAnDkGbqZMG9STKQA8ly8AAJkzAACZMgAAmTMAAP///wD///8A/H8AAPB/AADABwAAwAMAAMADAADgAwAA+EMAAPxDAADCPwAAwg8AAMAHAADAAwAAwAMAAPAHAAD+DwAA/j8AAA==';

 }
 else { this.image=
'data:image/x-icon;base64,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';

 };
}
  

function e4xConv_parseXULFromString(xul) {
    xul = xul.replace(/>\s+</g, "><");
    return new DOMParser().parseFromString(xul, "application/xml").documentElement;
}