ns4 = (document.layers)? true:false
ie4 = (document.all)? true:false
ns6 = (document.getElementById)? true:false

if (document.images) {

	nav1 = new Image();
	nav2 = new Image();
	nav3 = new Image();
	nav4 = new Image();
	
	nav1.src = "images/nav1.gif";
	nav2.src = "images/nav2.gif";
	nav3.src = "images/nav3.gif";
	nav4.src = "images/nav4.gif";
	
	nav1on = new Image();
	nav2on = new Image();
	nav3on = new Image();
	nav4on = new Image();
	
	nav1on.src = "images/nav1on.gif";
	nav2on.src = "images/nav2on.gif";
	nav3on.src = "images/nav3on.gif";
	nav4on.src = "images/nav4on.gif";
	
	}



function chgImg(imgField,newImg) {
	if (document.images) {
		document[imgField].src = eval(newImg + ".src")
	}
}