using lucene.net index and search txt and pdf files

Sir, I am trying to develop a search engine in asp.net using lucene.net. I go through many tutorials and pages to get the appropriate results but i couldn't. Actually I have a folder with some files(doc,ppt,pdf,excel etc..) and i want to search within that folder only for contents and if the results are not found within that folder then ask user to search on web.

for example i have a folder with thousands of files @ C:\test and if user searched for "miller" then it should search into every document. if results are found then it should display results like that

Searched text file no of occurences miller C:\test\1\file.doc 5 miller C:\test\1\11\new.doc 2

please help me i am not getting appropriate results .

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