Help getting this hack to work correctly

[X-Caliber]

I'm running 2.3.2

I just followed the instructions like it said.

Here is the Require call in the hack.

//variables
require("admin/global.php");

Here is the part where it connects to the database:

////////////////////////////////////////////////////////////////////////////////////////////
// connect to database server
$dbconnect = @mysql_connect($servername,$dbusername,$dbpassword );
if (!$dbconnect) {
exit();
}

//choose correct database
if (! @mysql_select_db($dbname) ) {
exit();
}

// define some constants
// message types
$type = array("text", "multipart", "message", "application", "audio", "image", "video", "other");
// message encodings
$encoding = array("7bit", "8bit", "binary", "base64", "quoted-printable", "other");

// remove extraneous stuff from email addresses
// returns an email address stripped of everything but the address itself
function clean_address(&$val, $index)
{
// clean out whitespace
$val = trim($val);
// look for angle braces
$begin = strrpos($val, "<");
$end = strrpos($val, ">");
if ($begin !== false)
{
// return whatever is between the angle braces
$val = substr($val, ($begin+1), $end-$begin-1);
}
}

Thanks for any help you can give me. I'm a n00b and learning.