ldap server can not replace the order of login, why?

[jiing]

<?php
$ldapServer="ld ap://192.168.1.211";
$ldapPort="389" ;
$ldapconn=ldap_ connect($ldapSe rver,$ldapPort) ;
$ldaprdn="uid=r oot, ou=People, dc=aitc, dc=com, dc=tw";
$ldappass="abcd ";

if($ldapconn){
echo "connect to ".$ldapServ er." successfully \n<br>";
}else{
echo "can't connect to LDAP server!\n<br>";
}
if ($ldapconn) {
// binding to ldap server to give update access
$ldapbind = ldap_bind($ldap conn, $ldaprdn, $ldappass);
// verify binding
if ($ldapbind) {
echo "LDAP binding successful...\n ";
} else {
echo "LDAP binding failed...\n";
}
}
//data preparation
//I am not very sure what attribute should be filled
$data["uid"]="tester";
$data["cn"]="Tester 1";
$data["objectclas s"][0]="account";
$data["objectclas s"][1]="posixAccount" ;
$data["objectclas s"][2]="top";
$data["userpasswo rd"]="tester";
$data["loginshell "]="/usr/local/bin/bash";
$data["uidnumber"]=3100;
$data["gidnumber"]=3100;
$data["homedirect ory"]="/home/tester";
$data["gecos"]="Tester 1";

// Before ldap_add(), should check the user already exists or not
if(!ldap_add($l dapconn,"uid=te ster, ou=People, dc=aitc, dc=com,
dc=tw", $data)){
echo "There is a problem to create the account\n";
echo "Please contact your administrator!\ n";
exit;
}else{
echo "account creation successfully";
}
ldap_close($lda pconn);
?>

I used ldapbrowser to connect LDAP server(openldap ), and I can see all
the user，but I can not Add Entry，but I can Delete Entry
Then I wrote the php code above to add a new user tester（the
$data fields are all the fields of LDAP, but some fields were filled
by me randomly，like uidnumber和gidnu mber）, but if
I do not fill those fields, it will occurs the following warning
message

Warning: ldap_add(): Add: Object class violation in
d:\AppServ\www\ LDAP_test1.ph
p on line 74
There is a problem to create the account
Please contact your administrator!

But I found the biggest problem is : my ldap server can not replace
the login order, i.e, I want to build accounts/passwords in openldap
server, then users can use the account/password in ldap server and
login freebsd server. But when I use the above php code to create a
tester account, the user "tester" still can not use tester/tester to
login freebsd host, why? Could you tell me.

Thanks in advanced.

-jiing-