Hide child pages in side bar

I’ve read other post about controlling the depth of the menu but it none it looks familiar when I look at the site’s code and I know pretty much nothing about php. This is just a quick change for the a none profit. The code is:

// menu list
echo ‘

‘;

// page ids in an array
$pageids = array(
“student” => 22,
“supporter” => 24,
“blog” => 9,
“about” => 20,
“parent” => 41,
“login” => 49
);

// check if parent page
if(in_array($post->ID,$pageids)) echo get_pagechildren($post->ID);
// subpage
else {

// gets parent pages
$parents = get_post_ancestors($post->ID);

// the last element in the array is the parent page
echo get_pagechildren($parents[count($parents)-1]);
}

echo ‘
‘;