<?php
$server = "dc.foo.com";
$username = "katie";
$password = "katiespassword";

ad_auth($server, $username, $password);

function ad_auth( $server, $username, $password ){
        $ldap = @ldap_connect( $server );

        if ( @ldap_bind( $ldap, $username, $password ) ){
                ldap_unbind( $ldap );
                echo("yay");
                return 1;
                }
        else{
                echo("boo");
                return 0;
                }
        }
?>