Expander - onExpand collapse all other elements?

Expander - onExpand collapse all other elements?

I would like to collapse all other elements before expand an element. There is a trigger (beforeExpand?) but I don't get it to work.
Any clues?
  1.   $('div.expandable p').expander({
  2. //...
  3.     beforeExpand function(){
  4.             $('div.expandable p').reCollapse();      //doesn't work :-(
  5.     }
  6.   });
best regards
manu