[Mediawiki-l] "Go" doesn't search for article title first

[Ross Xu]

Hi there,
As we know, the difference between "Go" and "Search" buttons beside the search box is that "Go" first looks for article's title and first lists search results found in titles, and immediately goes to the indicated article if one is found. If "Go" fails to find an article, it then automatically executes "Search" which is a full-text search for the given words.
 
However, it only works well for default namespaces. If the given keywords string is in articles under a customized namespace, the "Go" doesn't look for (or list) article titles first, which means there is no difference between "Go" and "Search".
 
Is there any way to do to make the "Go" to work for customized namespaces?
 
BTW, in case there is something to do with the search engine, I am using Lucene-search/MWSearch.
Thanks in advance,
Ross Xu