aspell dictionary

Hi,

I am new to aspell, I would like to use it for spell check in my project.
I include lib and dll of aspell in my project, but do not know how to
include dictionaries in it, so I have Error: No word lists can be found for
the language "en_US".
Anyone can guide me to install dictionaries in this case?

Thanks a lot!
-- 

Best,

Bo