LDAP Authentication, PHP

<?php
$ds=ldap_connect("***.***.**.**",389); // must be a valid LDAP server!
ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, 3);
ldap_set_option($ds, LDAP_OPT_REFERRALS, 0);
$r=ldap_bind($ds,$username,$password_ldap);
if($r){
$sr=ldap_search($ds, "DC=humaaaaa,DC=com", "(CN=*)") or die('LDAP SEARCH ERROR
');
//$sr=ldap_search($ds, "DC=".$domainname2[0].",DC=".$domainname2[1]."", "(CN=*)") or die('LDAP SEARCH ERROR
');
if(!$sr){
echo "<script>window.location='login.php?status=false'</SCRIPT>";
}else{

$noof_user=ldap_count_entries($ds, $sr); // calculate no. of records found
if($noof_user>=1){
$info=ldap_get_entries($ds, $sr);
for ($i=0; $i<$info["count"]; $i++) {
$givennname=$info[$i]["name"][0];

}

echo "<script>window.location='index.php?session_user=".$username."&access=valid'</SCRIPT>";
}else{
echo "<script>window.location='login.php?status=false'</SCRIPT>";
}
?>