Undefined offset: 2
You will have those notices, if either of those $pages indexes are not set. Check for the existence of the key before trying to use it. if (isset($pages[$current-1])) $prevID = $pages[$current-1]; if (isset($pages[$current+1])) $nextID = $pages[$current+1]; Or something along these lines … $prevID = (isset($pages[$current-1])) ? $pages[$current-1] : ”; $nextID = (isset($pages[$current+1])) ? $pages[$current+1] : … Read more