The first thing to do is to add some error handling to your script.
<?php
$link = mysql_connect("localhost", "mysql_user", "mysql_password");
mysql_select_db("nonexistentdb", $link);
echo mysql_errno($link) . ": " . mysql_error($link). "\n";
mysql_select_db("kossu", $link);
mysql_query("SELECT * FROM nonexistenttable", $link);
echo mysql_errno($link) . ": " . mysql_error($link) . "\n";
?>
By echoing the mysql_errno and mysql_error, you will get a plain text desciption if you are having any issues with your script.
Aside from that, I would check to make sure your user has privilages to create databases.