I am trying to add a second category box on the admin write page. I want one category box to contain commonly used categories and the second box to contain all categories.
In the wpedit-form-advanced.php file I found the code to produce the dropdown categories:
<fieldset id="categorydiv" class="dbx-box">
<h3 class="dbx-handle"><?php _e('Categories') ?></h3>
<ul id="categorychecklist"><?php dropdown_categories(); ?></div>
I repeated that code and it gave me a new box, but when I try to limit the categories with arguments, I couldn't get it to work. I've tried excluding, like this:
<?php dropdown_categories('exclude=1,3'); ?>
I've tried including categories too (which would be better, actually).
<?php dropdown_categories(2); ?>
Am I doing this wrong or missing something? Do I need to make changes elsewhere?