alpha with space regex in cakephp

I have a user registration form and I only want the user to specify their first and last name (i.e. Donalg Doonsberry). If the user doesn't provide their name in this fashion, the input will be rejected. I thought something like this would work for my regex user validation in cakephp:

  'name'=>array('Name has to be comprised of letters.
                '=>array('rule'=>array('custom', '/[A-Za-z ]+/')
           )),

From stackoverflow

• You have to be careful validating names... what about:

  • Donalg McDonald <- capital in the middle of a word
  • Donalg Fooble-Whiffery <- hyphenated
  • Donalg Déénsbnérry-McDonald Sr. 3rd <- you get the idea

  To validate names in the format you specified:

  /[A-Z][a-z]+ [A-Z][a-z]+/
  

  Being a bit more lenient:

  /([\w.-]+ )+[\w+.-]/
  

  Tomalak : +1 I second the notion that trying to validate human names with regex is nonsense. I'm not even sure what that would be good for.

  donalg d : how do you validate that the user inputs data that is not malicious?

  Greg : You shouldn't need to - you should escape it properly every time you use it - either in an SQL query (e.g. mysql_real_escape_string) or outputting to a page (e.g. htmlspecialchars)

• Personally, I wouldn't bother with first/last name validation. You can only validate their length (there is a built-in validation rule in cake for that) and make sure you put "allowEmpty" => true, if that's what you want.