Description
bool 
ctype_alpha ( string text )
   Checks if all of the characters in the provided string,
   text, are alphabetic.
   In the standard C locale letters are just 
   [A-Za-z] and ctype_alpha() is 
   equivalent to (ctype_upper($text) || ctype_lower($text))
   if $text is just a single character, but other languages have letters that 
   are considered neither upper nor lower case.