Facing problem while Accessing the chile grids in nested GridView

[Mudassar]

I am facing a problem while accessing the gridview in nested gridview
structure.
Some time i found child gridview control but when i bind data to child
gridview it doesnt appears or appear in first row or some time i got null
reference exception
if i tried again and again.

Please guide me if any one know the solution.

Thanks in advance
Mudassar