Use service in multiple modules AngularJS -

i have 2 modules should connected. main module, called mainpage has second module, called router, injected. in separate files. want use service called userpropagatorservice in mainpage , in router. service should used , set logged in user. tried inject service router module, errors. how can achieve this?

mainpage file:

var app = angular.module('mainpage',['reg','router']);  //returns promise generates our user. app.factory('userloginservice',['$http',function ($http){     return{      loginservice: function(username,password){          var info = {username:username, password:password}          var user={};          //returning http request because of promises         return $http({              url: 'webapi/users/login',             method: 'post',             data: info,             headers: {                 'content-type': 'application/x-www-form-urlencoded'             },             transformrequest: function(obj) {                 var str = [];                 for(var p in obj)                 str.push(encodeuricomponent(p) + "=" + encodeuricomponent(obj[p]));                 return str.join("&");             },             data:{username: info.username, password: info.password}          }).then(function (response)         {              user = response.data             return user;          });      }    } }]);   app.service('userpropagatorservice', function(){     return{         get:function(){             return this.u;        },         set:function(user){             this.u = user;         }    }  }); 

router file:

var r = angular.module('router',['ngroute'])     .config(['$routeprovider', '$locationprovider','userpropagatorservice',         function($routeprovider, $locationprovider, userpropagatorservice) {          $locationprovider.html5mode(true);          $routeprovider         .when("/home",{             templateurl: "pages/mainpage.html",             controller:"homecontroller"         })         .when("/forums",{             templateurl: "pages/forumspage.html",             controller:"forumcontroller"         })         .when("/topics",{             templateurl: "pages/topicspage.html",             controller:"topicscontroller"         })         .when("/comments",{             templateurl: "pages/commentspage.html",             controller:"commentscontroller"         })         .otherwise({             redirectto:"/home"         });     }])      .controller("homecontroller",['$scope','$http',function($scope,$http){          /*$http({             url: "webapi/forums/all",             method:"get"         })         .then(function(response){             console.log("yea!");             console.log(response.data);         },         function(response){             console.log("no:(");         })*/          $scope.username = "visitor!"         $scope.user = userpropagatorservice.get();         if($scope.user != null){             $scope.username=$scope.user.username + "!";         }      }])     .controller("forumcontroller",['$scope','$http',function($scope,$http){          $scope.username = "visitor!"      }])     .controller("commentscontroller",['$scope','$http',function($scope,$http){          $scope.username = "visitor!"      }]); 

if want use userloginservice in router module, needs broken out of main app.

var app = angular.module('mainpage',['reg','router']);  angular.module("services",[])   .factory('userloginservice',['$http',function ($http){      return{         //service code here     }; }]); 

then add dependency in router module:

var r = angular.module('router',['ngroute','services'])