Drop on area which is scrolled away

Drop on area which is scrolled away


Hi, I found the following problem:
Situation: Two divs, one is surrounding - let's say height: 300px and
width: 300px, another one is inside, but is bigger: height: 300px and
width 600px. The bigger one is a Droppable.
Now, the bigger one is not completely visible, and the smaller one
will have scroll bars. Still you are able to drop something on the
"invisible" or (scrolled away) part of of the bigger one.
Why? And can I prevent this (dropping only possible onto the visible
area of the bigger div)?
I hope you could understand what I mean.
Thanks in advance!
morres