UL and jQuery for a menu sliding up and down

UL and jQuery for a menu sliding up and down

Hi,
  1. level 1
  2.    level 2
  3.    level 2
  4.       level 3
  5.       level 3
  6.    level 2
  7. level 1
  8.    level 2
  9.    level 2
  10.    level 2
  11.       level 3
when user click on an item all subitem should be sliding up (if they are already visible) or down (if they are hidden).
this works well, however as it is under joomla, when user click on a level item, it load the page attached (into content div) by the level item link and the whole menu status/appearance is resetted :-(
it means that if all level 3 were slided up before clicking, after clicking and loading page, all level 3 are once again visible.

what can i do to avoid such situation ?

thanks.

A.