c# - RedirectToRoute doesn't work -

i'm making first web app. until haven't got problems redirecttoroute or redirecttoaction. @ end of post action want redirect, doesn't work @ here code:

   [httppost]     public actionresult delete(int id)     {         var post = this.data             .posts             .all()             .where(x => x.id == id)             .firstordefault();          if (post != null)         {             var thread = this.data                 .threads                 .all()                 .where(x => x.id == post.threadid)                 .firstordefault();              this.data                 .posts                 .delete(post);              this.data.savechanges();              return this.redirecttoroute(commonconstants.redirecttorouteshowthread, new             {                 area = "",                 id = thread.id,                 title = thread.subcategory.title,                 name = thread.title,                 action = "display"             });             //return this.redirecttoroute(commonconstants.redirecttorouteshowallthreadsinsubcategory, new { area = "", title = thread.subcategory.title });              // return this.redirect("red/red");         }          return this.view();     } 

i tried different redirects test, still doesn't work. i'am calling action js if matters. have checked if goes inside if conditional, seems fine. error?

edit: here routes

     public static void registerroutes(routecollection routes)     {         routes.ignoreroute("{resource}.axd/{*pathinfo}");          routes.maproute(             name: "show thread",             url: "subcategory/{title}/{action}/{id}-{name}/{page}",             defaults: new { controller = "post", action = "display", page = urlparameter.optional },             namespaces: new[] { "forumsystem.web.controllers" });          routes.maproute(             name: "create , display threads",             url: "subcategory/{title}/{action}/{page}",             defaults: new { controller = "subcategory", page = urlparameter.optional },             namespaces: new[] { "forumsystem.web.controllers" });          routes.maproute(             name: "default",             url: "{controller}/{action}/{id}",             defaults: new { controller = "home", action = "index", id = urlparameter.optional },             namespaces: new[] { "forumsystem.web.controllers" });     } 

and const

    public static readonly string redirecttorouteshowthread = "show thread"; 

what mean doesn't work doesn't redirect else working expected.