Drop-down Actions

[Chohan, Dharmesh]

Hi

I have got a requirement to dynamically update the action of one drop-down A 
and list the relevant items on drop-down B.

So drop-down A has Animals, Fruits, etc
On selection of Fruits drop-down B should list Apples, Oranges etc

Is this possible in ISIS and how to implement this behaviour?

Thanks in advance.
Dharmesh