Forms - Dependent Field Not populating with update

I have two dropdown on my form. For Parent & Child. Parent Drodown filled by :

SELECT [ParentID],Title FROM (SELECT NULL ParentID, '{%GetResourceString("Parent", QueryString["culture"].ToString()==""?QueryString["parentculture"]:QueryString["culture"])#%}' as Title, 0 AS SORTORDER UNION SELECT DH.ParentID, DH.TITLE, 1 AS SORTORDER FROM View_CMS_Tree_Joined_Publish V INNER JOIN K_Parent DH ON V.DocumentForeignKeyValue=Dh.ParentID
WHERE V.ClassName='K.Parent' AND V.DocumentCulture = '{%currentCulture%}' AND V.Published = 1) AS FOO ORDER BY SORTORDER, Title

Parent dropdown set as "Has Dependent Fields" == true.

Now the Child Dropdown set to dependent on another field = true. Also i have to bind dropdown for selected parent. but the child dropdown does not updated as per parent selection.

SELECT [ChildsID],Title,Parent FROM (SELECT NULL ChildsID, '{%GetResourceString("Child", QueryString["culture"].ToString()==""?QueryString["parentculture"]:QueryString["culture"])#%}' as Title,'' Parent, 0 AS SORTORDER UNION SELECT DD.ChildsID, DD.TITLE, Parent, 1 AS SORTORDER FROM View_CMS_Tree_Joined_Publish V INNER JOIN K_Childs DD ON V.DocumentForeignKeyValue=DD.ChildsID
WHERE V.ClassName='K.Childs' AND V.DocumentCulture = '{%currentCulture%}' AND V.Published = 1 AND (Parent = '{%Parent.Value#%}' or '{%Parent.Value#%}' = '') ) AS Childs ORDER BY SORTORDER, Title

Please let me know how can i achieve this.