javascript - Knockout.js Observable Not Getting Set -

i have code not doing suppose do. knockout.js project , object;

self.eventitem = ko.observable({   recordid: ko.observable(0),   selectedeventtype: ko.observable() } 

this object initialized in function. there lot of code in here debugging while shows "self.originaleventitem().eventtypeid" return value of "6" , number. value set selectedeventtype;

self.loadinitialdata = function () {          self.pageloaded(false);          var step1 = common.geteventdetailsforedit(self.eventitem().recordid()); //step1          var step2 = step1.then(             function (data) {                 if (data.iserror) {                     toastr.error(data.errormessage, "error");                     return new $.deferred().reject();                 } else {                     self.originaleventitem(data.data);                     return common.geteventtypes();                 }             }); //step2          var step3 = step2.then(             function (data) {                 if (data.length > 0) {                     $.each(data, function (i, item) {                         self.eventtypes.push(new apollo.dropdowntype(item.recordid, item.name));                         self.originaleventtypes.push(item);                     });                     self.eventitem().selectedeventtype(self.originaleventitem().eventtypeid);                     self.eventtypechanged();                  }             }         );//step3      };//loadinitialdata 

now when enter "self.eventtypechanged()" function , call "self.eventitem().selectedeventtype()" return undefined? here function "eventtypechanged()";

self.eventtypechanged = function () {         if (self.originaleventtypes) {             var newvalue = self.eventitem().selectedeventtype();             (var = 0; < self.originaleventtypes.length; i++) {                 if (self.originaleventtypes[i].recordid === newvalue) {                     self.eventitem().selectedfulleventtype(self.originaleventtypes[i]);                 }             }              self.resetlists();             self.populatechildlists();         }     }; 

the variable "newvalue" undefined. debugged way through knockout.js , looks being set reason not.

any appreciated.