Adding initial data to LDAP

["Marius Cabas" <marius_cabas@hotmail.com>]

I'm runnung an OpenLDAP server using the following slapd.conf data:

include  /usr/local/etc/openldap/core.schema

pidfile  /usr/local/var/slapd.pid
argsfile /usr/local/var/slapd.args

database ldbm
suffix  "o=vt"

rootdn  "cn=manager,o=vt"
rootpw  start

directory /usr/local/etc/openldap/openldap-ldbm
index objectClass eq

Now, i want to add some records to the LDAP database and for this i'm using
the following command:
ldapadd -f add.ldif -cxv -D "cn=manager,o=vt" -w start

The add.ldif file looks as follows:
dn: cn=myname,o=vt
cn: myname
sn: mysurname
objectclass: top
objectclass: person
userPassword: secret

After executing ldapadd, the output is like below:
ldap_initialize( <DEFAULT> )
add cn:
        myname
add sn:
        mysurname
add objectclass:
        top
        person
add userPassword:
        secret
adding new entry "cn=myname,o=vt"
ldap_add: No such object
        additional info: parent does not exist
ldif_record() = 32

What is the problem? What am I doing wrong?