LDIF with umlauts

["Bayer, Friedrich" <Friedrich.Bayer@beko.at>]

Hallo,
i want to add umlauts (like ä,ö, etc...) in my LDAP.
It's no problem if I use JNDI,
but if I want to add umlauts in LDIF-Data with the LDAPADD Command 
I always get this error message:

ldap_add: Invalid syntax 
additional info: sn: value #0 contains invalid data

Thanks for helping,
Fritz Bayer