You can call the files anything you want, but you will need to make the same change to the file names in the makefile.
thanks for your mail. Ok i shall do it . Can i rename the example driver.cc to relay.cc in my own directory. if not than if i want to make another driver than what shall i do? Because i need to make another 2/3 driver for my robot. if i rename than do i need to change the driver registry.cc and put it in my directory.