Propert for Child Grids in the parent datagrid with Toggle Button like plus and minus symbols

Hi,

 In my project when clicked on a row that should open another datagrid inside that parent grid and i am looking for a property where we can have a plus symbol as row header which indicates that the row has a child grid and when clicked on that plus button it should show the child grid and that plus button should change to minus button which when clicked closes the child grid....

something like HierarchyChildTemplate property.