Angular: Empty Fiddle

http://angularjs.org/

HTML

<script src="http://code.angularjs.org/angular-1.0.1.js"></script>
<div ng-controller="MyCtrl">
    <input type="text" ng-model="name" />

    <br/>
    
    <input type="text" ng-model="updatedname" />
    
    <input type="button" value="Change name" ng-click="changeName(updatedname)"/>
    <br/>
      Hello, {{name}}!
</div>

JavaScript

var myApp = angular.module('myApp',[]);
myApp.factory('UserService', function() {
            var userService = {};

            userService.name = "HI Atul";

            userService.ChangeName = function (value) {
               
                userService.name = value;
            };
    
    return userService;
});

function MyCtrl($scope, UserService) {
    $scope.name = UserService.name;
    $scope.updatedname="";
    $scope.changeName=function(data){
        $scope.updateServiceName(data);
    }
    $scope.updateServiceName = function(name){
        UserService.ChangeName(name);
        $scope.name = UserService.name;
    }
}