I know this may sound a bit obvious, but are you substituting ($dbmachine, $dbuser, and $dbpassword) with your specific information?
The code $mysql_link = mysql_connect($dbmachine, $dbuser, $dbpassword);
would look something like
The code $mysql_link = mysql_connect(localhost, yourusername, yourpassword);
or
you can define those variables in a different file and require it into your page.
so -
$dbmachine = localhost;
$dbuser = yourusername;
$dbpassword = yourpassword;
steve