How to get the current value of a select box?

Here is my code:

<input type="text" id="search_form" name="search" /> <%= observe_field 'search_form',                  :frequency => 0.5,                  :update => 'results',                  :url => { :controller => 'programs', :action=> 'get_results',                  :search_type => select_type }, # an error occurs                  :with => "'search_text=' + escape(value)"%> <%= select "select","type",{"BOY" => '1', "Girl" => '2'}%>

Can anyone tell me how to pass the value of the select box when i call "get_results"?