How to get an internal ng-model value? - angularjs

Question

I am working on SPA and I include HTML pages into one basic page by ng-include.Let's call this basic page as external and the included pages as internal.In an internal page I have set an input attribute to be ng-model="userd.Username" and in the external page i would like to get the value of this input.
In some internal page register.html there is the following code:
<div class="form-group">
<div class="form-group">
<span class="regForm text-danger">*</span> <input
ng-model="userd.Username" type="text" maxlength="10"
placeholder="Enter your name" class="form-control input-md"
required />
</div>
<div class="form-group">
<span class="regForm text-danger">*</span> <input
ng-model="userd.Password" type="password" maxlength="8"
placeholder="Enter your password" class="form-control input-md"
required />
</div>
<div class="form-group">
<span class="regForm text-danger">*</span><input
ng-model="userd.Nickname" type="text" maxlength="20"
placeholder="Enter your nickname" class="form-control input-md"
required />
</div>
<div class="form-group">
<input ng-model="userd.Description" type="text" maxlength="50"
placeholder="Enter description about you"
class="form-control input-md" />
</div>
<div class="form-group">
<input ng-model="userd.Photo" type="text"
placeholder="Enter photo URL" class="form-control input-md" />
</div>
<div class="form-group">
<button ng-click="registerBtn()" class="btn btn-primary">Register</button>
</div>
</div>
In the external page:
<div ng-include="'register.html'" ng-controller="registerCon" ng-show="logreg"></div>
I've tried to use the $rootscope as following in the main controller of the external page:
var appvar = angular.module('myApp', []);
//The Main Controller of the page (single web page)
appvar.controller('myCtrl',['$scope','$http','$rootScope',function($scope, $http,$rootScope) {
$rootScope.storedsession="";
}]);
And in the controller 'registerCon' I wrote:
appvar.controller('registerCon',['$scope','$http','$rootScope',function($scope, $http, $rootScope) {
$scope.registerBtn = function() {
console.log(this.userd);
$http.post("http://localhost:8080/ExampleServletv3/registeruser",this.userd)
.success(function(response) {
console.log(response);
setTimeout(function () {
$scope.$apply(function(){
$rootScope.storedsession=this.userd.Username;
console.log($rootScope.storedsession);
});
});
});
};
}]);
but it prints undefined for console.log($rootScope.storedsession); in the console,I also tried $scope instead of $rootScope but it didn't work too.
Can someone help me please?
Thanks