Re: FIR filter design question

>In windowing method for FIR design, you specify the frequency response of
>the desired filter at sample points fs/N, and perform an IDFT to obtain
>h(n).
>So doesnt this mean that you want fs to be as low as possible to specify
>better frequency resolution. But Fs is generally many times the cut-off
>frequency - more than the minimum of twice the cut off needed. 
>
>Why is this?Isn't the frequency resolution that I specify for the filter
>response going to be poorer as I choose higher Fs?
>
>


N is the size of FFT. I guess my question is, when I design this filter
using the IDFT method, if I had a choice how would I select Fs and why?