if(document.images) {

nav_home_on = new Image;
nav_home_off = new Image;
nav_about_on = new Image;
nav_about_off = new Image;
nav_what_on = new Image;
nav_what_off = new Image;
nav_contact_on = new Image;
nav_contact_off = new Image;

nav_home_on.src = "../image/royle_nav_home_on.gif";
nav_home_off.src = "../image/royle_nav_home_off.gif";
nav_about_on.src = "../image/royle_nav_about_on.gif";
nav_about_off.src = "../image/royle_nav_about_off.gif";
nav_what_on.src = "../image/royle_nav_what_on.gif";
nav_what_off.src = "../image/royle_nav_what_off.gif";
nav_contact_on.src = "../image/royle_nav_contact_on.gif";
nav_contact_off.src = "../image/royle_nav_contact_off.gif";

}

function swapImage(f,n) {
  f = "document."+f;
  f = eval(f);
  n = eval(n);
  f.src = n.src;
}