that is a mysql error. you probably need a valid username and password.
is the site you're developing and testing this on your local computer? or is it a web hosting company?
it's here:
PHP Code:
$conn = mysql_connect("localhost","username","password") or die ("Could not connect to mysql because ".mysql_error());
$db = mysql_select_db("klhgye") or die ("Could not select database because ".mysql_error());
notice where i entered 'username' and 'password' replace that with your valid login information.