var photos_page = 1;
var loaded_page = 0;
function photos_pageup()
{
	return photos_pageslide(-1);
}
function photos_pagedown()
{
	return photos_pageslide(1);
}
function photos_pageslide(updown)
{
	var oldpage = photos_page;
	photos_page += updown;
	if (photos_page < 1) photos_page = lastpage;
	if (photos_page > lastpage) photos_page = 1;
	
	if (photos_page == loaded_page && lastpage > 2)
	{
		photos_scroll(updown);
	}
	else
	{
		var update_div = 'photos' + (2 + updown);
		new Ajax.Updater(update_div, 'wp-content/themes/oasis/photoslider.php?page='+photos_page, 
			{
				onComplete: function () {
					photos_scroll(updown);
				}
			}); 
	}
	loaded_page = oldpage;
	return false;
}
function photos_scroll(updown)
{
	var update_div = 'photos' + (2 + updown);
	new Effect.Parallel([
		new Effect.Move(update_div, { sync: true, x: 0, y: 0, mode: 'absolute' }),
		new Effect.Move('photos2', { sync: true, x: 0, y: (updown * -1 * 652), mode: 'absolute' })
	], { 
	  	duration: 0.8,
	  	afterFinish: function () {
	  		if (updown == 1)
	  		{
		  		$('photos1').id = 'photos0';
		  		$('photos2').id = 'photos1';
		  		$('photos3').id = 'photos2';
		  		$('photos0').id = 'photos3';
		  		$('photos3').style.top = '652px';
		  	}
		  	else
		  	{
		  		$('photos3').id = 'photos0';
		  		$('photos2').id = 'photos3';
		  		$('photos1').id = 'photos2';
		  		$('photos0').id = 'photos1';
		  		$('photos1').style.top = '-652px';
		  	}
	  	}
	});
}