Janus GridEX SelfReferencing Setting

I want to Load my tree as Hirarchical in Janus GridEX , but when I set the setting it is not working , my table columns are:

TopicID nvarchar(50)  ; --which is parent
ParentID nvarchar(50) ;--which is child
Description nvarchar(50);

and the setting window is like as following

Also I checked with GridEX tutorial every thing is ok but not working for me !!

I did following settings and it works like a charm .