How can I add a custom attribute to the create page dialog?

I followed the following link to add a custom attribute called starred and this attaribute can be displayed in siteadmin grid

http://dev.day.com/docs/en/cq/current/developing/customize_siteadmin.h tml

I would like to let the user input the value when they create a page. That's why I would like to add a custom field in the input dialog box as attached pic.

The method you describe before can only added those CQ bulid-in attribute.

For those custom attribute, how can I added it?