[galaxy-user] generating random sequences

Hi,galaxy users, I'am wondering if there is a tool for generating random genome sequence or from a specific region(i.e. all promoter region).I known there is 'random intervals' in 'ENCODE Tools'.But the problem is it seems restricted to generating random sequence from 'ENCODE Regions' while i'd prefer whole genenome region. By the way, what is the statistical model for generating this random sequence? can i just random generate a series of genome coordinates and then extract the correponding sequences? If you had read some research articles descripting the random procedure, please suggest for me. Regards, Xu Jianzhen GIBH,CAS