OK, so in plugin options...
"1 - the BigWhat search engine will be searched if you pass in bw=1,
or if the search returns no results."
and...
"If you pass in bw=1 then the results will be available in your search_results.html using the regular tags. Otherwise, you must add the following tags: <%bigwhat_results%> - a list of the matching links."
Means that to use as a
No Links Result Return you set this to 1 in admin, and put in the search results template <%if link_results%><%link_results%><%else%><%bigwhat_results%><%endif%>
This works OK for a No Links Results and shows the BigWhat results as expected.
Now say you want an option on the search form to use BigWhat results ONLY, you force a bw=1 from, say, a check box.
Problem here is that no results are returned from the BigWhat engine using bw=1.
I'm sure this is all correct.
Eraser:
Insight Eye
http://www.insighteye.com/