Try:
^([a-zA-z,/.-]+)\s([a-zA-z,/.-]+)$
But ... if you are going to use Regular expressions, get a copy of
Expresso[
^] - it's free, and it examines and generates Regular expressions.
And that probably won't do exactly what you want, since first names don't normally contain hyphens, and no names other than idiot "celebrities" have slashes, decimal points, or commas in either the first or last name ... and some of those have "one one name" anyway.