[jQuery] Elements are still droppable while they're in the hidden part of a scrollable container

[jQuery] Elements are still droppable while they're in the hidden part of a scrollable container


Hi guys ,
I got this problem, and I think I'm missing something
You can check, i've put a example here : http://lickmychip.com/ =>
There, the hidden part is noticed with a dotted box.
How to do it the right way ?