I started developing a web service following samples that made use of
webservice.htc.  I have since found a way to call a web service with
javascript from a web page that is MUCH easier than using webservice.htc.  Is
webservice.htc obsolete?  Would webservice.htc have any advantage over this
approach?

namespace MyCompany.Services.Control
{
   [WebService(Namespace = "http://www.MyCompany.com/Services/Control/")]
   [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
   [ToolboxItem(false)]
   [ScriptService]
   public class FrameItemService : System.Web.Services.WebService
   {
       [WebMethod(EnableSession=true)]
       public string HelloWorld()
       {
       }
   }
}