Case insensitive search

Hi, I noticed that XWiki does case sensitive search, e.g. if I search for "available", available will be found, but not "Available." How can I make searches case insensitive? Speaking of searching, it not clear to me what happens if I turn on Lucene. Does this replace searching back-end for regular search box, or I have to add new page for searching? Regards, v Zeljko