PHP & MySQL noob error.

[deepode]

i m nt much pro in php & mysql but i find some scripts on web & understood(at least i think so) and now trying to run'em. I uploaded'em to server but they aren't working.

I think i shall tell you that website is (desired to) run on free server, the free domain has been registered and they are telling it will be active in 72 hours, till i am trying to try my code (i am given facility to preview). SO I want to know that..
1. Is there problem in script? if yes, where? (I don't think bcz, its from reliable website)
2. Is there problem in username & password, because i am reading (ref. errors below) "ACCESS DENIED"?
3. Do server needs to active to public before i can check this? I don't think so....because i think we can also make this work without internet as html pages.... can't we?Well leave it.
4. At lease i also request to give me technique to make log in system.
Sorry for any mistakes,Thanks in advance. Here are Scripts & Errors.

First Script named conf.inc.php :

<?php
$db_user = "u123_admin"; // Username
$db_pass = "admin1right"; // Password
$db_database = "u123_userbase"; // Database Name
$db_host = ""; // Server Hostname
$db_connect = mysql_connect ($db_host, $db_user, $db_pass); // Connects to the database.
$db_select = mysql_select_db ($db_database); // Selects the database.
 
function form($data) { // Prevents SQL Injection
   global $db_connect;
   $data = ereg_replace("[\'\")(;|`,<>]", "", $data);
   $data = mysql_real_escape_string(trim($data), $db_connect);
   return stripslashes($data);
}
?>

The second script named register.php:

<?php
include("conf.inc.php"); // Includes the db and form info.
if (!isset($_POST['submit'])) { // If the form has not been submitted.
    echo "<form action=\"register.php\" method=\"POST\">";
    echo "<table>";
    echo "<tr>";
    echo "<td colspan=\"2\">Register:</td>";
    echo "</tr>";
    echo "<tr>";
    echo "<td width=\"50%\">Username:</td><td width=\"50%\"><input name=\"username\" size=\"18\" type=\"text\" />";
    echo "</tr>";
    echo "<tr>";
    echo "<td width=\"50%\">Password:</td><td width=\"50%\"><input name=\"password\" size=\"18\" type=\"text\" />";
    echo "</tr>";
    echo "<tr>";
    echo "<td width=\"50%\">Email:</td><td width=\"50%\"><input name=\"email\" size=\"18\" type=\"text\" />";
    echo "</tr>";
    echo "<tr>";
    echo "<td colspan=\"2\"><input type=\"submit\" name=\"submit\" value=\"submit\"</td>";
    echo "</tr>";
    echo "</table>";
    echo "</form>";
} else { // The form has been submitted.
    $username = form($_POST['username']);
    $password = md5($_POST['password']); // Encrypts the password.
    $email = form($_POST['email']);
 
    if (($username == "") || ($password == "") || ($email == "")) { // Checks for blanks.
        exit("There was a field missing, please correct the form.");
    }
 
    $q = mysql_query("SELECT * FROM `users` WHERE username = '$username' OR email = '$email'") or die (mysql_error()); // mySQL Query
    $r = mysql_num_rows($q); // Checks to see if anything is in the db.
 
    if ($r > 0) { // If there are users with the same username/email.
        exit("That username/email is already registered!");
    } else {
        mysql_query("INSERT INTO `users` (username,password,email) VALUES ('$username','$password','$email')") or die (mysql_error()); // Inserts the user.
        header("Location: login.php"); // Back to login.
    }
}
mysql_close($db_connect); // Closes the connection.
?>

When i try to run this i receive errors:

Warning: mysql_connect() [function.mysql-connect]: Access denied for user 'u123_admin'@'localhost' (using password: YES) in /home/u123/public_html/conf.inc.php on line 6

Warning: mysql_select_db() [function.mysql-select-db]: Access denied for user 'root'@'localhost' (using password: NO) in /home/u123/public_html/conf.inc.php on line 7

Warning: mysql_select_db() [function.mysql-select-db]: A link to the server could not be established in /home/123/public_html/conf.inc.php on line 7

[ksushil970]

Either mysql is not running or mysql socket is in different place.

[NogDog]

You need to find out from your hosting provider (or your control panel there) what database host to use and what user/password credentials to use there -- or perhaps even if your account there includes MySQL at all?

[deepode]

Thanks, guys! I solved it, problem was in hostname, when i check server's faq, i see that they told to look in MySQL Database menu for hostname. I got it, thanks for your help. Sorry for that mistake.... .