vi posto il codice ;-)
Codice PHP:
if (mysql_num_rows($quer2)==0) {
session_destroy();//kills the session if user not in the database
UrlRedirect("login.php?error=1");
//header("login.php?error=2");
} else {
//success user is valid grab details from database and register them in the session
$userid = mysql_result($quer2,0,"id");
$username = mysql_result($quer2,0,"username");
$password2 = mysql_result($quer2,0,"password");
$name = mysql_result($quer2,0,"nome");
session_register("pracid");
session_register("username");
session_register("name");
session_register("password2");
}