WPF Drag and Drop (Grid to Grid)

WPF Drag and Drop (Grid to Grid)

I am trying to find a way to drag and drop between two grids(NOT datagrids).
I have one Main grid control with 24 columns and 24 rows and some other
grid which i want to Drag.
Thus in About Image there is two parts One is Drag and One is Drop Check
this => http://pho.to/3YMuu
Thus i want to Drag(Any Grid Like 3*3, 5*5 and 5*10) and Drop(24*24) to
Main Grid Like this => http://pho.to/3YMwI
i want to Drag grid(3*3, 5*5, 5*10) and Drop in to Grid(24*24) in any Cell.
when i drop the Grid, it will just highlight in Main Grid(24*24).
Plese Help Me.
Sorry for My English