Angular: Empty Fiddle

http://angularjs.org/

HTML

<script src="http://code.angularjs.org/angular-1.0.1.js"></script>
<div ng-controller="MyCtrl">
  Value:, {{test}}!
</div>

<div ng-controller="SetCtrl">
   <input ng-model="newTestVal" placeholder="Enter value to set">
       <button ng-click="setTestVal(newTestVal)">Set value</button>
</div>

JavaScript

var myApp = angular.module('myApp',[]);

myApp.factory('myService', function() {
    var test = 5;
    
    return{
      setTestVal: function(val){
        test = val;
      },
      getTestVal: function(){
        return test;      
      }
    }

    
});

function MyCtrl($scope, myService) {
    $scope.test = myService.getTestVal();
}

function SetCtrl($scope, myService){
    $scope.newTestVal = '';
    $scope.setTestVal = function(val){
      myService.setTestVal(val)
    }
}