jquery - ASP.Net C# website functionality not working on iis -

i have website built in asp.net c# , jquery functionality. find functionality (eg delete files) not work unless step through code in debug mode. none of functionality works on site on localhost (iis)

i using file handler (filetransferhandler.ashx)to delete, upload files. said above works when step through code in debug mode not when run on localhost(iis)

the error seem getting is: 405 page looking cannot displayed because invalid method (http verb) being used

here code

using system.collections.generic; using system.configuration; using system.io; using system.linq; using system.web; using system.web.script.serialization; using system.web.sessionstate;  public class filetransferhandler : ihttphandler, ireadonlysessionstate {     private readonly javascriptserializer js = new javascriptserializer();       public string storageroot     {          { return configurationmanager.appsettings["storageroot"] ; }     }     public bool isreusable { { return false; } }      public void processrequest(httpcontext context)     {         context.response.addheader("pragma", "no-cache");         context.response.addheader("cache-control", "private, no-cache");          handlemethod(context);     }      // handle request based on method     private void handlemethod(httpcontext context)     {         switch (context.request.httpmethod)         {             case "head":             case "get":                 if (givenfilename(context)) deliverfile(context);                 else listcurrentfiles(context);                 break;              case "post":             case "put":                 uploadfile(context);                 break;              case "delete":                 deletefile(context);                 break;              case "options":                 returnoptions(context);                 break;              default:                 context.response.clearheaders();                 context.response.statuscode = 405;                 break;         }     }      private static void returnoptions(httpcontext context)     {         context.response.addheader("allow", "delete,get,head,post,put,options");         context.response.statuscode = 200;     }      // delete file server     private void deletefile(httpcontext context)     {         var filepath = storageroot + context.session["uname"].tostring() + "/" + context.request["f"];         if (file.exists(filepath))         {             file.delete(filepath);         }     }      // upload file server     private void uploadfile(httpcontext context)     {         var statuses = new list<filesstatus>();         var headers = context.request.headers;          if (string.isnullorempty(headers["x-file-name"]))         {             uploadwholefile(context, statuses);         }         else         {             uploadpartialfile(headers["x-file-name"], context, statuses);         }          writejsoniframesafe(context, statuses);     }      // upload partial file     private void uploadpartialfile(string filename, httpcontext context, list<filesstatus> statuses)     {         if (context.request.files.count != 1) throw new httprequestvalidationexception("attempt upload chunked file containing more 1 fragment per request");         var inputstream = context.request.files[0].inputstream;         var fullname = storageroot+ context.session["uname"].tostring() + "/"  + path.getfilename(filename);          using (var fs = new filestream(fullname, filemode.append, fileaccess.write))         {             var buffer = new byte[1024];              var l = inputstream.read(buffer, 0, 1024);             while (l > 0)             {                 fs.write(buffer, 0, l);                 l = inputstream.read(buffer, 0, 1024);             }             fs.flush();             fs.close();         }         statuses.add(new filesstatus(new fileinfo(fullname)));     }      // upload entire file     private void uploadwholefile(httpcontext context, list<filesstatus> statuses)     {         (int = 0; < context.request.files.count; i++)         {             var file = context.request.files[i];             file.saveas(storageroot + context.session["uname"].tostring()+ "/"  + path.getfilename(file.filename));              string fullname = path.getfilename(file.filename);             statuses.add(new filesstatus(fullname, file.contentlength));         }     }      private void writejsoniframesafe(httpcontext context, list<filesstatus> statuses)     {         context.response.addheader("vary", "accept");         try         {             if (context.request["http_accept"].contains("application/json"))                 context.response.contenttype = "application/json";             else                 context.response.contenttype = "text/plain";         }         catch         {             context.response.contenttype = "text/plain";         }          var jsonobj = js.serialize(statuses.toarray());         context.response.write(jsonobj);     }      private static bool givenfilename(httpcontext context)     {         return !string.isnullorempty(context.request["f"]);     }      private void deliverfile(httpcontext context)     {         var filename = context.request["f"];         var filepath = storageroot  + context.session["uname"].tostring() + "/"+ filename;          if (file.exists(filepath))         {             context.response.addheader("content-disposition", "attachment; filename=\"" + filename + "\"");             context.response.contenttype = "application/octet-stream";             context.response.clearcontent();             context.response.writefile(filepath);         }         else             context.response.statuscode = 404;     }      private void listcurrentfiles(httpcontext context)     {         var files =             new directoryinfo(storageroot + "/" + context.session["uname"].tostring())                 .getfiles("*", searchoption.topdirectoryonly)                 .where(f => !f.attributes.hasflag(fileattributes.hidden))                 .select(f => new filesstatus(f))                 .toarray();          string jsonobj = js.serialize(files);         context.response.addheader("content-disposition", "inline; filename=\"files.json\"");         context.response.write(jsonobj);         context.response.contenttype = "application/json";     } } 

even had faced issue after clearing cookie , cache of browser, has been resolved.