if (document.images) {

// preload inactive images
nav1= new Image();
nav1.src="home.png";

nav2= new Image();
nav2.src="about.png";

nav3= new Image();
nav3.src="staff.png";

nav4= new Image();
nav4.src="services.png";

nav5= new Image();
nav5.src="order.png";

nav6= new Image();
nav6.src="intakeforms.png";

nav7=new Image();
nav7.src="links.png";

nav8=new Image();
nav8.src="email.png";

nav9=new Image();
nav9.src="contact.png";
// preload active images
nav1on= new Image();
nav1on.src="home2.png";

nav2on= new Image();
nav2on.src="about2.png";

nav3on= new Image();
nav3on.src="staff2.png";

nav4on= new Image();
nav4on.src="services2.png";

nav5on= new Image();
nav5on.src="order2.png";

nav6on= new Image();
nav6on.src="intakeforms2.png";

nav7on= new Image();
nav7on.src="links2.png";

nav8on= new Image();
nav8on.src="email2.png";

nav9on=new Image();
nav9on.src="contact2.png";
}

function img_act(imgName) {
if (document.images) {
imgOn = eval(imgName + "on.src");
document [imgName].src = imgOn;
}
}

function img_inact(imgName) {
if (document.images) {
imgOff = eval(imgName + ".src");
document [imgName].src = imgOff;
}
}