if (document.images) {
nav1 = new Image ();
nav1.src = "blank.gif";
nav2 = new Image ();
nav2.src = "line.gif";
nav3 = new Image ();
nav3.src = "line.gif";
nav4 = new Image ();
nav4.src = "line.gif";

nav1r = new Image ();
nav1r.src = "arrow.gif";
nav2r = new Image ();
nav2r.src = "arrow.gif";
nav3r = new Image ();
nav3r.src = "arrow.gif";
nav4r = new Image ();
nav4r.src = "arrow.gif";
}

function On (imgName) {
	if (document.images) {
		document [imgName].src = eval (imgName + "r.src");
		}
}
function Off (imgName) {
	if (document.images) {
		document [imgName].src = "blank.gif";
		document [imgName].src = eval (imgName + ".src");
	}
}