Sortable_element doesn't update div nor call onComplete func

Rails
1

I have a sortable UL with LIs in it

example:

<%= sortable_element("my_list", { :complete => "alert ('hi')", :handle => "drag", :update => "menu", :url => { :action => "order_menu" } } ) %>

nothing happens, nothing at all, after I have changed the order and
dropped the item in its new position. Why?

thanks