Error: [$injector:undef] in angualrjs

Hi ,

I created a service and injected that into a controller.But getting error like "Error: [$injector:undef] http://errors.angularjs.org/1.6.9/$injector/undef?p0=addlabtestsvc"

what would be the error?

Please respond ASAP.

controller:

var app=angular.module('AddlabTest',[]);
app.controller("AddlabTestcontroller",['$scope','addlabtestsvc',function($scope,addlabtesttsvc)
{
$scope.msg="Angularexample";
$scope.SaveToLabtest=function()
{
alert("");
addlabtestsvc.addItem();
}
}]);

Service:

"use strict";
(function()
{
angular.module('AddlabTest')
.factory('addlabtestsvc',function()
{
var addItem = function()
{
alert("message");
};
});
})();