Select Tag

Hi,

I am new to rubyonrails..i have some dought using select tag.
I created two tables with name of districts and taulks..both table
have id and name.I load all data from districts table
view:
<% select ("districts" , options_for_select(@all)) %>
controller:
@all = District.find(:all)

now i want select data from ditricts table then corresponding data
will be displayed by taulks (using dropdownbox).

Ex: i click one district name means then the taulks name willbe
diplayed by taulks select tag..

what can i do ? plzz help me..