sub gen_nav_link
{
my ($label, $start_pos) = @_;
my @param =		# parameters to extract from environment
(
	# page control parameters
	"max_rec", "page_size",
	# search parameters
	"description"
);
my $url;

	# tell the script to continue the search and which record to start with
	$url = url () . "?choice=search;start_pos=$start_pos";

	# add other page control and search parameters
	foreach my $name (@param)
	{
		my @val = param ($name);
		# if a parameter has multiple values, add it multiple times
		foreach my $val (@val)
		{
			$url .= ";$name=" . escape ($val);
		}
	}
	return (a ({-href => $url}, escapeHTML ($label)));
}