LDAP Simple bind in PHP

<?php
$ldaphost = "ldap.xxx.yyy"; 
$ldapport = 389; 

$ds = ldap_connect($ldaphost, $ldapport) or die("Could not connect to $ldaphost"); 
ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, 3);
if ($ds) { 
 $username = "test"; 
 $upasswd = "password"; 
 $binddn = "cn=admin,dc=xxx,dc=yyy"; 
 $binddnt = "ou=mathematicians,dc=xxx,dc=yyy"; 
 $ldapbind = ldap_bind($ds,$binddn, $upasswd); 

 //check if ldap was sucessfull 
 if ($ldapbind) {
    $filter = "(uniqueMember=*)";
    $result = ldap_search($ds, $binddnt, $filter) or exit("Unable to search LDAP server");
 $entries = ldap_get_entries($ds, $result);
 var_dump($entries);
 } else {
    echo "LDAP bind failed...";
 }
}


?>