if (document.images)
{
home_on = new Image();
home_on.src = "images/nav_home_on.png";
home_off = new Image();
home_off.src = "images/nav_home_off.png";

about_on = new Image();
about_on.src = "images/nav_about_on.png";
about_off = new Image();
about_off.src = "images/nav_about_off.png";

speaking_on = new Image();
speaking_on.src = "images/nav_speaking_on.png";
speaking_off = new Image();
speaking_off.src = "images/nav_speaking_off.png";

endorsements_on = new Image();
endorsements_on.src = "images/nav_endorsements_on.png";
endorsements_off = new Image();
endorsements_off.src = "images/nav_endorsements_off.png";

store_on = new Image();
store_on.src = "images/nav_store_on.png";
store_off = new Image();
store_off.src = "images/nav_store_off.png";

resources_on = new Image();
resources_on.src = "images/nav_resources_on.png";
resources_off = new Image();
resources_off.src = "images/nav_resources_off.png";

media_on = new Image();
media_on.src = "images/nav_media_on.png";
media_off = new Image();
media_off.src = "images/nav_media_off.png";

contact_on = new Image();
contact_on.src = "images/nav_contact_on.png";
contact_off = new Image();
contact_off.src = "images/nav_contact_off.png";

blog_on = new Image();
blog_on.src = "images/nav_blog_on.png";
blog_off = new Image();
blog_off.src = "images/nav_blog_off.png";
}

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

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