ASP.Net AJAX没有创建Javascript类型

I'm using ASP.Net AJAX and I created a web service in my application. The service has one method (AddWatchedFolder) and it takes a Name.Space.WatchedFolder as the only parameter. The problem is, ASP.Net AJAX isn't generating a javascript type for Name.Space.WatchedFolder even though I've added the service to a ScriptManager.I'm using ASP.Net AJAX and I created a web serv