function toggle(caller_id, target_id)
{
	targetDiv = document.getElementById(target_id);
	
	if(targetDiv.style.display == 'block')
	{
		targetDiv.style.display = 'none';
		document.getElementById(caller_id).style.backgroundImage = 'url(./img/right_title_closed.png)';
	}
	else
	{
		targetDiv.style.display = 'block';
		document.getElementById(caller_id).style.backgroundImage = 'url(./img/right_title_open.png)';
	}
}