//function to turn images on.
function imgOn (img1) 
{
	if (document.images) 
	{
		document.images[img1].src = eval (img1 + "on.src");
	}
}
	
//function to turn images off.
function imgOff (img1) 
{
	if (document.images) 
	{
		document.images[img1].src = eval (img1 + "off.src");
	}
}