[BioC] biomaRt question

[Dipl.-Ing. Johannes Rainer]

hi,

as i am behind a http proxy and the biomart package tries to establish 
a direct mysql connectioj to the ensembl database i had no chance to 
test or use the biomaRt package.
well, now i finally managed to install a local version of biomart 
(after some problems i had with different versions of mysql (i strongly 
recommend to use MySQL > 4.1 !)). my question is now, how and where do 
i have to change biomaRt source to connect to my local biomart database?
another question: which mart database uses biomaRt, i assume the 
ensemble_mart and not the uniprot and msd mart...

cheers, jo