aspell -a option

Hi there,
  I am using aspell to do spell check. I would like to correct the spelling 
errors in the document automatically. I know I can use the interactive mode to 
pick the one you want. How about non-interactive mode? From the archive, I see 
that you can use "aspell list" to obtain the words that are in error. How about 
the correction. If I use the "aspell -a" option, do they still use the aspell 
algorithm instead of the Ispell one? I think I tried the aspell -a > newfile and 
got the list of words that are identified as errors and showed all the choices. 
Is it the only way to do? Is there a simpler way to like simply feed the file 
into aspell and magically feed out the modified document with all the words 
corrected using, say, the first suggestion. I know it will not be perfect but it 
saves a lot of time etc. 

I am using the Windows 0.53.0 or something like that.

Thanks.

Anthony