function switchImg(m_sImageName, m_sState)
{
	if (document.images)
	{
		imgSource = document[m_sImageName].src;
		if (m_sState == "on")
		{
			onState = imgSource.replace(/_off/i,"_on");
			document[m_sImageName].src = onState;
		}
		else 
		{
			offState = imgSource.replace(/_on/i,"_off");
			document[m_sImageName].src = offState;
		}
	}
}

if (document.images)
{
  a = new Image(); a.src = "images/menu_about_on.jpg";
  b = new Image(); b.src = "images/menu_contact_on.jpg";
  c = new Image(); c.src = "images/menu_gallery_on.jpg";
  d = new Image(); d.src = "images/menu_krisk_on.jpg";
  e = new Image(); e.src = "images/menu_services_on.jpg";
  f = new Image(); e.src = "images/menu_shop_on.jpg";
}

function rollOn(imgName)
{
	if (document.images)
	{
		document[imgName].src = eval(imgName + '_on.src');
	}
}

function rollOff(imgName)
{
	if (document.images)
	{ 
		document[imgName].src = eval(imgName + '_off.src');
	}
}