if (document.images)  {

var img1on = new Image();
img1on.src = "images/home_button_over.jpg";
var img2on = new Image();
img2on.src = "images/application_button_over.jpg";
var img3on = new Image();
img3on.src = "images/gallery_button_over.jpg";
var img4on = new Image();
img4on.src = "images/how_button_over.jpg";
var img5on = new Image();
img5on.src = "images/profile_button_over.jpg";
var img6on = new Image();
img6on.src = "images/equipment_button_over.jpg";
var img7on = new Image();
img7on.src = "images/contact_button_over.jpg";
var img8on = new Image();
img8on.src = "images/graffity1_over.jpg";
var img9on = new Image();
img9on.src = "images/graffity2_over.jpg";
var img10on = new Image();
img10on.src = "images/whynot_button_over.jpg";

var img1off = new Image();
img1off.src = "images/home_button.jpg";
var img2off = new Image();
img2off.src = "images/application_button.jpg";
var img3off = new Image();
img3off.src = "images/gallery_button.jpg";
var img4off = new Image();
img4off.src = "images/how_button.jpg";
var img5off = new Image();
img5off.src = "images/profile_button.jpg";
var img6off = new Image();
img6off.src = "images/equipment_button.jpg";
var img7off = new Image();
img7off.src = "images/contact_button.jpg";
var img8off = new Image();
img8off.src = "images/graffity1.jpg";
var img9off = new Image();
img9off.src = "images/graffity2.jpg";
var img10off = new Image();
img10off.src = "images/whynot_button.jpg";
}

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");
   }
}