PHP and regexp to accept only Greek characters in form

Question

I need a regular expression that accepts only Greek chars and spaces for a name field in my form (PHP). I\'ve tried several findings on the net but no luck. Any help will be

Answer 1

Full letters solution, with accented letters:

/^[A-Za-zΑ-Ωα-ωίϊΐόάέύϋΰήώ]+$/