function navergaasie($titles, $pointer, $list_size, $page_size) {
	if (!$titles) die("Cannot make navigation list. No titles found.");
	if (!$pointer or !array_search($pointer, $titles)) $pointer = $titles[0];
	if ($list_size<9) $list_size = 9;
	if ($page_size<1) $page_size = 1;
	$flank_size = ceil(($list_size-5)/2)+2;
	$page_count = ceil(count($titles)/$page_size);
	$current_page = ceil((array_search($pointer, $titles)+1)/$page_size);
	$left_flank = $current_page-$flank_size;
	$right_flank = $current_page+$flank_size;
	if ($left_flank<1) {
		$left_flank = 1;
		$right_flank = 1+2*$flank_size;
		if ($right_flank>$page_count) $right_flank = $page_count;
	}
	if ($right_flank>$page_count) {
		$right_flank = $page_count;
		$left_flank = $right_flank-2*$flank_size;
		if ($left_flank<1) $left_flank = 1;
	}
	for ($n=$left_flank; $n<$right_flank+1; $n++) {
		$page_numbers[] = $n;
	}
	foreach ($page_numbers as $page_number) {
		$page_link = $titles[($page_number-1)*$page_size];
		if ($page_link==$pointer) {
			$index[$page_number] = 
				"<li class=\"selected\">$page_number</li>";
		}
		else {
			$index[$page_number] = 
				"<li><a href=\"./?list=$page_link\">$page_number</a></li>";
		}
		if ($left_flank>1) {
			$page_link = $titles[0];
			$index[$left_flank] = 
				"<li><a href=\"./?list=$page_link\">1</a></li>";
			$index[$left_flank+1] = 
				"<li>...</li>";
		}
		if ($right_flank<$page_count) {
			$page_link = $titles[($page_count-1)*$page_size];
			$index[$right_flank] = 
				"<li><a href=\"./?list=$page_link\">$page_count</a></li>";
			$index[$right_flank-1] = 
				"<li>...</li>";
		}
	}
	ksort($index);
	$navigation_list = 
		"<ul id=\"navigation\">\n".implode("\n", $index)."\n</ul>";
	return($navigation_list);
}