if (document.images)  {

var img1on = new Image();
img1on.src = "images/home/topnav2_over.gif";
var img2on = new Image();
img2on.src = "images/home/topnav3_over.gif";
var img3on = new Image();
img3on.src = "images/home/topnav4_over.gif";
var img4on = new Image();
img4on.src = "images/home/topnav5_over.gif";
var img5on = new Image();
img5on.src = "images/home/topnav6_over.gif";
var img6on = new Image();
img6on.src = "images/home/topnav7_over.gif";
var img7on = new Image();
img7on.src = "images/home/topnav8_over.gif";
var img8on = new Image();
img8on.src = "images/home/topnav9_over.gif";

var img1off = new Image();
img1off.src = "images/home/topnav2.gif";
var img2off = new Image();
img2off.src = "images/home/topnav3.gif";
var img3off = new Image();
img3off.src = "images/home/topnav4.gif";
var img4off = new Image();
img4off.src = "images/home/topnav5.gif";
var img5off = new Image();
img5off.src = "images/home/topnav6.gif";
var img6off = new Image();
img6off.src = "images/home/topnav7.gif";
var img7off = new Image();
img7off.src = "images/home/topnav8.gif";
var img8off = new Image();
img8off.src = "images/home/topnav9.gif";
}

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

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