How to delete a build definition from TFS?

 public bool DeleteBuildDef(IBuildServer service, string TeamProject, string BuildDefinition)
        {
       
            try
            {
                var def = service.GetBuildDefinition(TeamProject, BuildDefinition, QueryOptions.Definitions);
                service.DeleteBuilds(def.QueryBuilds());
                def.Delete();
                return true;
            }
            catch
            {
                return false;
            }

        }