c# - Asp.net MVC Cascading Dropdownlist for Single Model -

i trying implement cascading dropdownlist tutorials 2 or more relational tables. have model below, , there no limit subcategory(in model whstockcardgroup) level.

when user select main whstockcardgroup (from first level of tree), need create new dropdownlist in same page , fill related sub categories , on.

i have looked @ tutorials http://www.codeproject.com/articles/258172/simple-implementation-of-mvc-cascading-ajax-drop-d not create new dropdown , fill sub-categories.

 public class whstockcardgroup     {         public int id { get; set; }          public string name { get; set; }         public int? relatedwhstockcardgroupid { get; set; }         public virtual whstockcardgroup relatedwhstockcardgroup { get; set; }           public boolean lastchild { get; set; }         public boolean firstchild { get; set; }     }