drop once but trigger twice in drop event

drop once but trigger twice in drop event


hi,
There are a couple of "DIV" ,one is on the top and the other is
below it. Let's call the top one TOP,and the below one BELOW.
Now the TOP contains many sub-DIV set to "float:right" that make
the TOP "overflow",so some sub-DIV are hidden into the back of BELOW.
Both sub-DIV and BELOW are set droppable for the pictures in
them,and both of them have set action for drop event, for example
"alert('hello')"; of course, the pictures are draggable.
Now the problem comes while dragging picture from sub-DIV in TOP
to BELOW. If the area where the pictrue drops is just where the sub-
DIV hides,the drop event is triggered twice,that is 'hello' alert
twice. And the picture factly drops into the sub-DIV ,not BELOW that I
expected.
I want the picture drops into the BELOW ,but it drops into the sub-
DIV;I want the event set in BELOW is triggered,but both event of
BELOW and sub-DIV are triggered. How to resolve the problem,thanks.