ASP.NET web application index based search engine

How to develope index based searching in ASP.NET web application?
Lucence.NET(formerly DotLucence) is the fastest open source search engine for .NET.
http://www.dotlucene.net/
download from here
http://www.dotlucene.net/tools
online demo
http://www.dotlucene.net/demo/
tools ,demo and samples
http://www.dotlucene.net/tools
now dotlucence.net was closed but dont worry,But all Dotlucence library updated versions available on sourceforge.net
http://sourceforge.net/project/showfiles.php?group_id=119263
codeproject offers  implement index based searching in our  ASP.NET web application
check here : http://www.codeproject.com/useritems/Search_with_in_documents.asp