-- << put processes inside the architecture section >>
-- (you can have multiple processes in an architecture, but beware of multiple drivers!)
-- (you can mix processes and signal assignments in any order within the arch.)

process(prs, rst) -- "listen" for changes of the prs and rst inputs (key pressed, reset)
                  -- note that you can have other processes that also listen to these
                  -- the process will execute only when there is a change on one(or more)
                  -- of the lines.  All signal assignments done in a process stay at that
                  -- value until the processes changes them.
begin
  if rst = '1' then
    -- stuff to do if reset is asserted (put your reset code here)
  else
    -- stuff to do normally
    if prs'event and prs = '1' then  -- this is called a "clock edge selection",
                                     -- you'll learn about that later.
                                     -- It just says that when prs CHANGES TO A 1, then
                                     -- do this stuff. (ie WHEN line gets raised, do this
                                     -- stuff once)
      -- stuff to do when a key is pressed (put main code here)
    end if;
  end if;
end process;