var current_segment = -1;
var segments = 0;
function nextArticleSegment(target, markerclass) {
	if (segments == 0) {
		segments = $$('ul.'+markerclass+' li');
	}
	if (segments.length > 0 && current_segment < (segments.length - 1)) {
		++current_segment;
		$(target).innerHTML = segments[current_segment].innerHTML;
		showBackward();
		showForward();
	}
}
function prevArticleSegment(target, markerclass) {
	if (segments == 0) {
		segments = $$('ul.'+markerclass+' li');
	}
	if (segments.length > 0 && current_segment > 0) {
		--current_segment;
		$(target).innerHTML = segments[current_segment].innerHTML;
		showBackward();
		showForward();
	}
}
function showBackward() {
	if (current_segment > 0) {
		$('backward').setStyle('display', 'inline');
	}
	else {
		$('backward').setStyle('display', 'none');
	}
}
function showForward() {
	if (current_segment < (segments.length - 1)) {
		$('forward').setStyle('display', 'inline');
	}
	else {
		$('forward').setStyle('display', 'none');
	}
}
function showMore(direction) {
	switch (direction) {
	case 'backward':
		if (current_segment < 1) {
			$('backward').setStyle('display', 'none');
		}
		else {
			$('backward').setStyle('display', 'visible');
		}
		break;
	case 'forward':
		if (current_segment < (segments.length - 1)) {
			$('forward').setStyle('display', 'inline');
		}
		else {
			$('forward').setStyle('display', 'none');
		}
		break;
	}
}