Hi!
I try to use select form as explain in guide but I have this error:

Call to a member function enumValues() on a non-object in E:\_silverstripe_cms\itesa\mysite\code\Page.php on line 51

Why?

in my page.php , under the page controller I put this function

function DropForm{
$field = new DropdownField(
'Country',
'Country',
singleton('MyObject')->dbObject('Country')->enumValues()
);
}

and I create MyobjectField.php with this class

class MyObject extends DataObject {
static $db = array(
'Country' => "Enum('New Zealand,United States,Germany','New Zealand')"
);
}

MyobjectField.php MUST have a class inside called "MyobjectField". If this isn't the case, SS will not detect the class.

In your case, just rename MyobjectField.php to MyObject.php, run ?flush=1 and you're set.

Sean