// function to swap circle image on
	   function circleOn(imgName) {
	   if (document.images) {
		document.images[imgName].src = "Images/on.gif";
	   }
	}
// function to swap circle image off
	   function circleOff(imgName) {
	   if (document.images) {
		document.images[imgName].src = "Images/off.gif";
	   }
	}