var nav_aboutbookOn = new Image();
nav_aboutbookOn.src = "images/nav_aboutbookOn.gif";
Ê
var nav_aboutbookOff = new Image();
nav_aboutbookOff.src = "images/nav_aboutbookOff.gif";
Ê
var nav_excerptOn = new Image();
nav_excerptOn.src = "images/nav_excerptOn.gif";
Ê
var nav_excerptOff = new Image();
nav_excerptOff.src = "images/nav_excerptOff.gif";
Ê
var nav_aboutauthorOn = new Image();
nav_aboutauthorOn.src = "images/nav_aboutauthorOn.gif";
Ê
var nav_aboutauthorOff = new Image();
nav_aboutauthorOff.src = "images/nav_aboutauthorOff.gif";
Ê
var nav_moreOn = new Image();
nav_moreOn.src = "images/nav_moreOn.gif";
Ê
var nav_moreOff = new Image();
nav_moreOff.src = "images/nav_moreOff.gif";

// Change RollOver
function menuRollOn(imgname){ //use this for mouseover on images NOT on layers
		if (document.all){
			eval('document.images.'+imgname+'.src='+imgname+'On.src');
		} else if (document.layers) {
			eval('document.'+imgname+'.src='+imgname+'On.src');
		} else if (document.getElementById&&!document.all) {
			eval('document.getElementById("'+imgname+'").src='+imgname+'On.src');
			//eval('document.'+imgname+'.src='+imgname+'On.src');
		}		
}

// Revert to Default Image
function menuRollOff(imgname) { //use this for mouseout on images NOT on layers
		if (document.all) {
			eval('document.images.'+imgname+'.src='+imgname+'Off.src');
		} else if (document.layers) {
			eval('document.'+imgname+'.src='+imgname+'Off.src');
		} else if (document.getElementById&&!document.all) {
			// doesn't work -- eval('document.'+imgname+'.setAttribute("src","'+imgname+'Off.src")');
			eval('document.getElementById("'+imgname+'").src='+imgname+'Off.src');
		}	  
}