commit in plpgsql function?

Hi,

I am converting oracle stored procedures to plpgsql. There are several 
of the oracle procedures where a parameter vCommit is passed into the 
procedure and:

if vCommit = 1  then      commit;      do_something_commit(vdate);  else      do_something(vdate);  end if;

does this make sense in plpgsql? Does it make sense to do a commit in 
plpgsql?

Thanks,

Dennis