javascript - history.back in backbone seems don't work -

i'm trying use windows.history.back() nothing happens. when event call history.back appear few second or less menu of previous page.

below view function called:

               var landscapeview = backbone.view.extend({     template: handlebars.compile(template),   events: {    },    initialize: function() {       this.geolocation();       $(window).on('orientationchange', this.onorientationchange);      },    /*    render: function() {       //var context = json.parse(json.stringify(this.model));//eliminare       //var context=this.model;       var html =this.template();        this.$el.html(html);         $('#pagina').empty();        $('#pagina').append(this.$el.html(html));         return this;     },*/         geolocation:function(){      navigator.geolocation.getcurrentposition(win);     function win(pos){         console.log("gps");        /* var el='<div>'+ pos.coords.latitude+'</div>';         el+='<div>'+ pos.coords.longitude+'</div>';         el+='<div>'+ pos.timestamp+'</div>';         $('#pagina').html(el);*/        var lat=pos.coords.latitude;     var lon=pos.coords.longitude;      var options={          center:new google.maps.latlng(lat,lon),         zoom:15,         maptypeid: google.maps.maptypeid.roadmap      };        var html=$('#pagina');       console.log(html);     var map= new google.maps.map(document.getelementbyid('pagina'),options);                   console.log(map);        };          },        onorientationchange: function() {  if(window.orientation === 0) {    window.history.back();         }     }              });   return landscapeview;    }); 

and here view previous history.back can't re-call:

          var homeview = backbone.view.extend({    template: handlebars.compile(template),   events: {   "click .log_out":"log_out",   "click .prove":"prove",    },    initialize: function() {        console.log("inhomeview");       this.render();      $(window).on('orientationchange', this.onorientationchange);      },        render: function() {       //var context = json.parse(json.stringify(this.model));//eliminare       var context=this.model;       var html =this.template(context);       console.log(html);       this.$el.html(html);            $('#pagina').empty();        $('#pagina').append(this.$el.html(html));         return this;     },       onorientationchange: function() {  if(window.orientation === 90 || window.orientation === -90) {    new landscapeview();          }     },                 log_out:function(){         console.log("logout");         parse.user.logout();      //   new appview;//errore undefined not function      window.location='index.html'  ;//mettere una new appview ma da errore!!!     },      prove:function(){      navigator.geolocation.getcurrentposition(win);     function win(pos){         console.log("gps");        /* var el='<div>'+ pos.coords.latitude+'</div>';         el+='<div>'+ pos.coords.longitude+'</div>';         el+='<div>'+ pos.timestamp+'</div>';         $('#pagina').html(el);*/        var lat=pos.coords.latitude;     var lon=pos.coords.longitude;      var options={          center:new google.maps.latlng(lat,lon),         zoom:15,         maptypeid: google.maps.maptypeid.roadmap      };        var html=$('#pagina');       console.log(html);     var map= new google.maps.map(document.getelementbyid('pagina'),options);                   console.log(map);        };          }    });   return homeview;     }); 

and router:

  var approuter = backbone.router.extend({      routes: {         "": "home",         "user/:objectid":"prova",         "settings":"settings",//mettere id dell utente loggato         "friends":"friends",         "mailbox":"mailbox"     },         home: function() {             console.log("inrouter");                   new appview();                },    settings: function(){      console.log("settings");      var view=new settingsview();      $('#pagina').html(view.render().el);    },  friends: function(){      console.log("friends");      var view=new friendsview();      $('#pagina').html(view.render().el);    }   ,  mailbox: function(){ console.log("mailbox");      }          });  return approuter;  }); 

and here main history starts:

       document.addeventlistener("deviceready", run, false);      run();      function run() {          var sync = backbone.sync;  backbone.sync = function(method, model, options) {  options.beforesend = function (xhr) {   xhr.setrequestheader('x-parse-application-id', 'qs0klmx5h9lflg**yhm9eepits3vmk');   xhr.setrequestheader('x-parse-rest-api-key', 'nh3eouo9g**vbf2gmhckjifit1gm');   };    sync(method, model, options);  },          app = new approuter();         backbone.history.start();          parse.$ = jquery;        parse.initialize("qs0klmx5h9l****tyhm9eepits3vmk",                "h4m*****agobqlwzrdw8irpdpf9qln7duy");      }