[Plugin: WP About Author] Cannot remove authorbox from posts

Hi all,

I’m a noob in CSS and PHP, but I cannot remove the authorbox from posts. I read the FAQ and it said:

<?php
function my_wp_about_author_display($author_content){
    if(is_page(100))
        return "";
    return $author_content;
}
add_filter('wp_about_author_display', 'my_wp_about_author_display');
?>

Now that is for a page. I edited if(is_page(100)) to if(is_page(ID)).

Then my WP crashed. What did I do wrong? The author box is showing in my contactforms and stuff. I’m using the Simple Catch theme.

http://ww.wp.xz.cn/extend/plugins/wp-about-author/