whitespace in validation

[eluser]Vikeoar[/eluser]
I'm validating a form and using the alpha_dash method with the validation library.

How do I allow for white space in a name? ie. "firstname lastname" without the quotes of course. I tried the trim method but the validation still gets stuck on the name field.

Is there a better method to validate a name that contains whitespace?

I suppose I could break the form up into two separate fields, firstname and lastname.

Any thoughts?

Thanks in advance.