var scroll_x = 0;
var scroll_y = 0;
var speed = 3;
var prev_x = -100000;
var prev_y = -100000;

function scroll_vertical(n, d) {
	var div = document.getElementById(d);
	var height = div.clientHeight;
	var y = div.scrollTop;

	scroll_y = y + (n * height);
	scroll_y = scroll_y < 0 ? 0 : scroll_y;

	if (div.scrollHeight - scroll_y < height) {
		scroll_y = div.scrollTop + div.scrollHeight - scroll_y;
	}

	t1 = setTimeout("scroll('" + d + "')", 50);
}

function scroll_horizontal(n, d) {
	var div = document.getElementById(d);
	var width = div.clientWidth;
	var x = div.scrollLeft;

	scroll_x = x + (n * width);
	scroll_x = scroll_x < 0 ? 0 : scroll_x;

	if (div.scrollWidth - scroll_x < width) {
		scroll_x = div.scrollLeft + div.scrollWidth - scroll_x;
	}

	t1 = setTimeout("scroll('" + d + "')", 50);
}

function scroll(d) {
	var div = document.getElementById(d);
	var new_x = (scroll_x - div.scrollLeft) / speed;
	var new_y = (scroll_y - div.scrollTop) / speed;
	var timeout = false;

	div.scrollLeft += new_x;
	div.scrollTop += new_y;

	if (new_x != prev_x) {
		prev_x = new_x;
		timeout = true;
	}

	if (new_y != prev_y) {
		prev_y = new_y;
		timeout = true;
	}

	if (timeout) {
		t1 = setTimeout("scroll('" + d + "')", 50);
	}
}


function showhide_img (src) {
 document.getElementById('gallery_target').src = src;
}