$(function()
{
	$(".columnize").columnize({ columns: 2});

	isBusy = false;
	currentPage = 0;
	totalPages = $('.columnize').length;

	if (totalPages > 1)
	{
		$('#middle .columnize:not(:first)').hide();
		$('#middle').append('<div id="js-pagination"></div>');
		makeNavigation(false, true);
	}
});

function makeNavigation(previousEnabled, nextEnabled)
{
	navigation = '<div class="previous">';
	if (previousEnabled)
	{
		navigation += '<a href="#">';
		navigation += '<img src="images/back.png" alt="&laquo; Previous" />';
		navigation += '</a>';
	}
	else navigation += '<img src="images/back_disabled.png" alt="&laquo; Previous" />';
	navigation += '</div>';

	navigation += '<div class="next">';
	if (nextEnabled)
	{
		navigation += '<a href="#">';
		navigation += '<img src="images/next.png" alt="Next &raquo;" />';
		navigation += '</a>';
	}
	else navigation += '<img src="images/next_disabled.png" alt="Next &raquo;" />';
	navigation += '</div>';

	$('#js-pagination').html(navigation);
	$('#js-pagination .previous a').click(previousClick);
	$('#js-pagination .next a').click(nextClick);
}

function previousClick()
{
	if (isBusy) return false;
	isBusy = true;

	$('#middle .columnize').eq(currentPage).fadeOut(function()
	{
		$('#middle .columnize').eq(currentPage - 1).fadeIn();
		currentPage--;
		if (currentPage == 0) makeNavigation(false, true);
		else makeNavigation(true, true);
		isBusy = false;
	});

	return false;
}

function nextClick()
{
	if (isBusy) return false;
	isBusy = true;

	$('#middle .columnize').eq(currentPage).fadeOut(function()
	{
		$('#middle .columnize').eq(currentPage + 1).fadeIn();
		currentPage++;
		if (currentPage == totalPages - 1) makeNavigation(true, false);
		else makeNavigation(true, true);
		isBusy = false;
	});

	return false;
}