(PHP 4 >= 4.0.6, PHP 5)
mb_substr — Get part of string
$str
   , int $start
   [, int $length = NULL
   [, string $encoding = mb_internal_encoding()
  ]] )
   Performs a multi-byte safe
   substr() operation based on
   number of characters. Position is
   counted from the beginning of
   str. First character's position is
   0. Second character position is 1, and so on. 
  
strThe string to extract the substring from.
start
       Position of first character to use from str.
      
length
       Maximum number of characters to use from str. If
       omitted or NULL is passed, extract all characters to
       the end of the string.
      
encodingThe encoding
parameter is the character encoding. If it is omitted, the internal character
encoding value will be used.
   mb_substr() returns the portion of
   str specified by the
   start and
   length parameters.