How to integrate SMF with another user database?

[rubix123]

I am using SMF 2.0.2 and the php script here http://www.ampjuke.org/. AmpJuke uses a MySQL database and has its own user system and registration. How would I go about integrating SMF with that user system? Any information to help me get started on the right path would be appreciated. 

Here is the login code for AmpJuke, could I change this to SMF some how and then add the AmpJuke tables to the SMF database?

$connection=mysql_connect($db_host,$db_user,$db_password) or die('Could not connect.');
mysql_select_db($db_name) or die('Could not select database !');

// 0.3.7: Changed two statements from $HTTP_POST_VARS to $_POST.
// 0.7.2: Ensure we ONLY accept letters+numbers:
$user=ereg_replace('[^a-zA-Z0-9]', "", $_POST['login']);
$pw=ereg_replace('[^a-zA-Z0-9]', "", $_POST['password']);

$qry="SELECT * FROM user WHERE name='$user' AND password='$pw'";

// 0.6.7: Take table-prefixes into account:
if (isset($ampjuke_tbl_prefix)) {
   $qry=str_replace("FROM ", "FROM $ampjuke_tbl_prefix", $qry);
}   
$result=mysql_query($qry)
   or die('Could not select a username from the user-table. Have you installed AmpJuke correctly ?');

Currently you have to make an account for each the forum and AmpJuke script. How can I put them together into 1 account?

[Kindred]

Look at the integration functions, if you want SMF to be the primary user system, or the SMF API if you want the other system to be the primary