How to connect to the CRM 2011 online webservice in REST (Jscript)?

I have find this website from microsoft msdn (http://msdn.microsoft.com/en-us/library/hh223541.aspx) where they are talking about CRUD functionality in REST (Jscript). there is also an example available which you can download: OptionSetSampleJScript.zip . When I download it and press F5 in Visual Studio, it gives me an error. Thats normal because I didnt enter my crm online url somewhere. I have find the location where the url is defined and found this piece of code:

var ServerUrl = this._Context().getServerUrl();
  if (ServerUrl.match(/\/$/)) {
   ServerUrl = ServerUrl.substring(0, ServerUrl.length - 1);
  }
  return ServerUrl + "/XRMServices/2011/OrganizationData.svc";

I have change it to:

var ServerUrl = "https://mycompany.crm4.dynamics.com";
  if (ServerUrl.match(/\/$/)) {
   ServerUrl = ServerUrl.substring(0, ServerUrl.length - 1);
  }
  return ServerUrl + "/XRMServices/2011/OrganizationData.svc";

I have run the application again, and it gives me another error. Access denied. How can I access my crm 2011 online webservice to do some crud functionity in REST?

ps. On the website of microsoft msdn they say this is also possible for CRM 2011 online.