Description
string 
mb_substr ( string str, int start [, int length [, string encoding]] )
     mb_substr() returns the portion of
     str specified by the
     start and
     length parameters.
    
     mb_substr() performs 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. 
    
     If encoding is omitted, internal encoding
     is assumed.
    
     encoding is character encoding. If it is
     omitted, internal character encoding is used.
    
     See also mb_strcut(), 
     mb_internal_encoding().