function img_on(name)
{
  $(name+'_img').src='images/menu/'+name+'_on.jpg';
}

function img_off(name)
{
  $(name+'_img').src='images/menu/'+name+'_off.jpg';
}

var current_service = null;

function show_service(name)
{
	if(current_service != null )
		$(current_service).style.display = 'none';
	current_service = name;
	$(name).style.display = 'block';
}