function clmSwitchWindows() {
			if (document.getElementById("ThumbLayer").style.visibility == "visible"){
				document.getElementById("ImageViewer").style.visibility = "visible";
				document.getElementById("ThumbLayer").style.visibility = "hidden"; }			
			else {
				document.getElementById("ImageViewer").style.visibility = "hidden";
				document.getElementById("ThumbLayer").style.visibility = "visible";	}
		} // end clmSwitchWindows