Sweave and the prompt

Hi the list

I would also like to remove the prompt, in order to let the reader 
cut-and-paste from pdf to R. So I set the prompt to " " with

options(prompt=" ",continue=" ")

But it add an extrat space at the start of each line. I also try some code
options(prompt="\a",continue="\a")
After a big figth in my office (my college did not like my new prompt 
:-) ), I gave up since it does not let the user cut-and-paste either...

Is there any possibility to completly remove the prompt ?

Thanks

Christophe