<?php    
$db_host = '127.0.0.1';    
$db_user = 'логин';    
$db_pass = 'пароль';    
$msconnect=mssql_connect("$db_host","$db_user","$db_pass");    

function unban()    
{    
    $sql = "DELETE FROM rf_user.dbo.tbl_UserBan WHERE nPeriod = 24";    
    $res = mssql_query ($sql);    
    if ($res) $text.="Баны сняты"; else $text.= "Ошибка!";    
    return $text;    
}    
echo unban();