In the Tree Grid example :!.../treegrid.html

I have modify the example in the above link and added one more column of xtype 'checkcolumn'.

Now my requirement is as follows :

1. If the checkbox corresponding to parent folder ( Project: Shopping in the above example ) is checked then
the checkboxes for all their children will be enable.

2. And if the checkbox of the parent folder is unchecked then the checkboxes for all the children will be disable.

If anybody has any idea then please share it. It is very urgent. Thanks in advance