prova cosi'
e solo dopo fai la selectCodice PHP:
$dbhost = "localhost";
$dbuser = "utente";
$dbpwd = "password";
$dbname = "nomedatabase";
$connessione = mysql_connect($dbhost,$dbuser,$dbpwd) or die("no connect");
$sel = mysql_select_db($dbname); or die("no db");