Authorize files in a folder

Hi

I'm using forms authentication I want to authorize a folder that contains a gif,pdf,htm files through code . I mean in the code I want to check a particular user say Ram and only then these files should be allowed to open else they should not be allowed .Is this possible through the same web.config file that is there for whole application instead of creating a separate one for that folder. I also want that the user should not be allowed to access these files through URL
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