function $(id)
{
	return document.getElementById(id);
}

function showHide(titleId, groupId)
{
	dis = $(groupId).style.display;
	if(dis=='block')
	{
		$(groupId).style.display = 'none';
		titleId.style.backgroundImage = 'url('+root_path+'/images/plusik.jpg)';
	}
	else
	{
		$(groupId).style.display = 'block';	
		titleId.style.backgroundImage = 'url('+root_path+'/images/minusik.jpg)';
	}
}