switching between requestHandler

[Jonathan Vanasco]

I'm assuming this is simple, and I'm just completely not finding the  
answer in the docs...

I have two request handlers based on dismax
  <requestHandler name="site_search_main" class="solr.SearchHandler" >
  </requestHandler>
  <requestHandler name="site_search_main_extended_fields"  
class="solr.SearchHandler" >
  </requestHandler>

How can i support both ?

I've only figured out how to have one active, and its killing me.