var position = 1;

function image_scroller_right()
{
	if (position != document.getElementById('number_of_examples').value - 3)
	{
		position = position + 1;
		document.getElementById('is_left').style.display = "inline";
	}
	else
	{
		document.getElementById('is_right').style.display = "none";
	}

	scroll();
	return false;
}

function image_scroller_left()
{
	if (position != 1)
	{
		position = position - 1;
		document.getElementById('is_right').style.display = "inline";
	}
	else
	{
		document.getElementById('is_left').style.display = "none";
	}

	scroll();
	return false;
}

function scroll()
{
	for (a=1;a<=document.getElementById('number_of_examples').value;a=a+1)
	{
		if (a >= position & a < position + 4)
		{
			document.getElementById('example' + a).className = "";
		}
		else
		{
			document.getElementById('example' + a).className = "hidden";
		}
	}
}