upgradesafe.php

<?php

// this file is upgrade safe
// location: custom/modules/Contacts/views/view.detail.php

require_once('modules/Contacts/views/view.detail.php');

class CustomContactsViewDetail extends ContactsViewDetail {
    /**
     * @see SugarView::display()
     *
     * We are overriding the display method to manipulate the portal information.
     * If portal is not enabled then don't show the portal fields.
     */
    public function display()
    {
        // my custom code here

        // call up the ContactsViewDetail Code to run the display after we have called
        // all of our custom code.
        parent::display();
    }
}