reset Drag and drop when jumping to next slide

Hi all ,

I have created a few drag and drop questions, 

thought some how they act differently.

I want to allow the user to drag and drop his answers, And not to save the action, 

so when the user comes back to the slide, he can start again fresh, with no trails.

follow the link: 

static.lnet.org.il/dev/sl/olim/3/story.html

have a look at D&D on slide number 4, and on slide number 8 - somehow the act different

soory for the Hebrew, the 2 bottons on the bottom are prev and next

I will appreciate eny help, 

Itamar.