var scrollanim = {position:0, time:0, begin:0, change:0.0, duration:0.0, timer:null};
var firefox_width = null

//(c) 2006 Valerio Proietti (http://mad4milk.net). MIT-style license.
function sineInOut(t, b, c, d) { return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b; }

function go_forward() {
	start_scroll(scrollanim.position, scrollanim.position - 656)
}

function go_backward() {
	start_scroll(scrollanim.position, scrollanim.position + 656)
}

function start_scroll(start, end) {
	if (scrollanim.timer != null) {
		clearInterval(scrollanim.timer);
		scrollanim.timer = null;
	}
	if(end > 0) { end = 0 };
	
	scroll_width = $('track').scrollWidth
	if(window.innerHeight && window.scrollMaxY) {
    if(!firefox_width) { firefox_width = $('train').scrollWidth - 656 }
    if(end < (firefox_width * -1)) { end = firefox_width * -1 }
	} else {
	  if(end < ((scroll_width - 656) * -1)) {end = ((scroll_width - 656) * -1)};
	}
	scrollanim.time = 0
	scrollanim.begin = start
	scrollanim.change = end - start
	scrollanim.duration = 25
	scrollanim.timer = setInterval("scroll_box();", 15);
}

function scroll_box() {
	if (scrollanim.time > scrollanim.duration) {
		clearInterval(scrollanim.timer);
		scrollanim.timer = null;
	}
	else {
		move = sineInOut(scrollanim.time, scrollanim.begin, scrollanim.change, scrollanim.duration);
		scrollanim.position = move
		$("track").style.marginLeft = scrollanim.position + "px";
		scrollanim.time++;
	}
}

function show_photo(id) {
	new Ajax.Request("/site/gallery_image", {
		method: 'get',
		parameters: {id: id},
		onSuccess: function(transport) { $('photo_viewer').update(transport.responseText) }
	})
}