word matching using asp.net

I don't think if you can achieve it from C# or Asp.net alone. You need to refer to the Database from where you'll be matching the user's entered text. If you're using SQL Server then do research on FreeText search. There's various functions available like "Sound" that will do the search for two similar sounding words and return the result based on Rank. This is the most powerful way for text search and showing the recommendations of what you used is looking for. 
But yes you need to find other ways to get the result faster. 

Thanks.